diff --git a/README.md b/README.md
index 4e5454da..e08e3537 100644
--- a/README.md
+++ b/README.md
@@ -29,12 +29,12 @@ Basic objects are:<br>
  - Hit (position and signal)<br>
  - Module (id and signal)<br>
 Four mentioned objects are so-called channelized:
-they contain set of channels (namely tracks, prticles, hits or modules) in each event<br>
+they contain set of channels (namely tracks, particles, hits or modules) in each event<br>
  - EventHeader (vertex position) - contains information related to specific event<br>
  - DataHeader - contains common information for all events<br>
  - Matching - establishes a correspondence between channels in channelized objects (e.g. between simulated particle and reconstructed track).
 
-Additionaly to mandatory information specified in round brackets (a.k.a. "default fileds"), each object can contain any number of integer, floating or boolean fields (a.k.a. "user-defined fields").
+Additionally to mandatory information specified in round brackets (a.k.a. "default fields"), each object can contain any number of integer, floating or boolean fields (a.k.a. "user-defined fields").
 Information about all fields in all branches is stored in Configuration object.
 
 ## Installation
diff --git a/core/BranchConfig.hpp b/core/BranchConfig.hpp
index e11ecdc3..2ca97c29 100644
--- a/core/BranchConfig.hpp
+++ b/core/BranchConfig.hpp
@@ -113,7 +113,7 @@ class BranchConfig : public VectorConfig<int>, public VectorConfig<float>, publi
   }
   template<typename T>
   void AddFields(const std::vector<std::string>& names, const std::string& title = "") {
-    for (auto& n : names) {
+    for (const auto& n : names) {
       GuaranteeFieldNameVacancy(n);
     }
     VectorConfig<T>::AddFields(names, title);
@@ -127,7 +127,7 @@ class BranchConfig : public VectorConfig<int>, public VectorConfig<float>, publi
   void RemoveField(const std::string& name);
 
   void RemoveFields(const std::vector<std::string>& names) {
-    for (auto& n : names) {
+    for (const auto& n : names) {
       RemoveField(n);
     }
   }
diff --git a/core/Configuration.cpp b/core/Configuration.cpp
index 36eba277..e8fc0ffc 100644
--- a/core/Configuration.cpp
+++ b/core/Configuration.cpp
@@ -65,7 +65,7 @@ BranchConfig& Configuration::GetBranchConfig(const std::string& name) {
 }
 
 const BranchConfig& Configuration::GetBranchConfig(const std::string& name) const {
-  for (auto& branch : branches_) {
+  for (const auto& branch : branches_) {
     if (branch.second.GetName() == name)
       return branch.second;
   }
@@ -187,7 +187,7 @@ void Configuration::RemoveBranchConfig(const std::string& branchname) {
 
 std::vector<std::string> Configuration::GetMatchesOfBranch(const std::string& branchname) const {
   std::vector<std::string> matches{};
-  for (auto& ma : matches_) {
+  for (const auto& ma : matches_) {
     if (ma.GetFirstBranchName() == branchname || ma.GetSecondBranchName() == branchname)
       matches.emplace_back(ma.GetDataBranchName());
   }
diff --git a/core/Configuration.hpp b/core/Configuration.hpp
index 4cc2d7e4..1f180d99 100644
--- a/core/Configuration.hpp
+++ b/core/Configuration.hpp
@@ -102,7 +102,7 @@ class Configuration : public TObject {
 
   static MatchingIndex MakeMatchingIndex(const std::vector<MatchingConfig>& matches) {
     MatchingIndex result;
-    for (auto& match : matches) {
+    for (const auto& match : matches) {
       std::array<std::string, 2> map_key{match.GetFirstBranchName(), match.GetSecondBranchName()};
       auto emplace_result = result.emplace(map_key, match.GetDataBranchName());
       if (!emplace_result.second) {
@@ -114,7 +114,7 @@ class Configuration : public TObject {
 
   static std::vector<MatchingConfig> MakeMatchConfigsFromIndex(const MatchingIndex& matching_index) {
     std::vector<MatchingConfig> result;
-    for (auto& matching_index_element : matching_index) {
+    for (const auto& matching_index_element : matching_index) {
       result.emplace_back(matching_index_element.first[0],
                           matching_index_element.first[1],
                           matching_index_element.second);
@@ -130,10 +130,10 @@ class Configuration : public TObject {
     * @param other
     */
   void Merge(const Configuration& other) {
-    for (auto& other_branch : other.branches_) {
+    for (const auto& other_branch : other.branches_) {
       const auto other_id = other_branch.second.GetId();
       const auto other_name = other_branch.second.GetName();
-      for (auto& local_branch : branches_) {
+      for (const auto& local_branch : branches_) {
         if (other_id == local_branch.second.GetId()) {
           throw std::runtime_error("Configurations contain branches with the same id-s");
         }
diff --git a/infra/AnalysisEntry.cpp b/infra/AnalysisEntry.cpp
index 69808c1d..e784132a 100644
--- a/infra/AnalysisEntry.cpp
+++ b/infra/AnalysisEntry.cpp
@@ -9,7 +9,7 @@
 namespace AnalysisTree {
 
 AnalysisEntry::~AnalysisEntry() {
-  for (auto& br : branches_) {
+  for (const auto& br : branches_) {
     delete br.first;
   }
 }
@@ -45,7 +45,7 @@ bool AnalysisEntry::ApplyCutOnBranches(std::vector<const Branch*>& br, std::vect
     id_vec.emplace_back(br.at(i)->GetId());
   }
   bool result = ok && (!cuts_ || cuts_->Apply(bch_vec, id_vec));
-  for (auto& bv : bch_vec) {
+  for (const auto& bv : bch_vec) {
     delete bv;
   }
   return result;
@@ -77,7 +77,7 @@ double AnalysisEntry::FillVariable(const Variable& var, std::vector<const Branch
     id_vec.emplace_back(br.at(i)->GetId());
   }
   double result = var.GetValue(bch_vec, id_vec);
-  for (auto& bv : bch_vec) {
+  for (const auto& bv : bch_vec) {
     delete bv;
   }
   return result;
@@ -116,7 +116,7 @@ void AnalysisEntry::FillFromEveHeaders() {
   br_vec.reserve(branches_.size());
   cuts_vec.reserve(branches_.size());
   id_vec.reserve(branches_.size());
-  for (auto& br : branches_) {
+  for (const auto& br : branches_) {
     br_vec.emplace_back(br.first);
     cuts_vec.emplace_back(br.second);
     id_vec.emplace_back(0);
@@ -154,7 +154,7 @@ void AnalysisEntry::FillFromOneChannalizedBranch() {
     br_vec.emplace_back(br.first);
     cuts_vec.emplace_back(br.second);
   }
-  for (auto& ehi : eve_header_indices_) {
+  for (const auto& ehi : eve_header_indices_) {
     id_vec.at(ehi) = 0;
   }
 
@@ -195,7 +195,7 @@ void AnalysisEntry::FillFromTwoChannalizedBranches() {
     br_vec.emplace_back(br.first);
     cuts_vec.emplace_back(br.second);
   }
-  for (auto& ehi : eve_header_indices_) {
+  for (const auto& ehi : eve_header_indices_) {
     id_vec.at(ehi) = 0;
   }
 
@@ -216,7 +216,7 @@ void AnalysisEntry::FillFromTwoChannalizedBranches() {
 }
 
 void AnalysisEntry::FillBranchNames() {
-  for (auto& var : vars_) {
+  for (const auto& var : vars_) {
     const auto& br = var.GetBranches();
     branch_names_.insert(br.begin(), br.end());
   }
@@ -236,7 +236,7 @@ void AnalysisEntry::Init(const Configuration& conf, const std::map<std::string,
   var4weight_.Init(conf);
 
   int i{0};
-  for (auto& bn : branch_names_) {
+  for (const auto& bn : branch_names_) {
     if (conf.GetBranchConfig(bn).GetType() == DetType::kEventHeader) {
       eve_header_indices_.push_back(i);
     } else {
diff --git a/infra/Branch.cpp b/infra/Branch.cpp
index cc2fc8fa..c7b68db0 100644
--- a/infra/Branch.cpp
+++ b/infra/Branch.cpp
@@ -107,7 +107,7 @@ void Branch::ClearChannels() {
 
 void Branch::CloneVariables(const AnalysisTree::BranchConfig& other) {
   auto import_fields_from_map = [this](const std::map<std::string, ConfigElement>& map, AnalysisTree::Types type) {
-    for (auto& element : map) {
+    for (const auto& element : map) {
       auto field_name = element.first;
       if (config_.HasField(field_name)) {
         std::cout << "Field '" << field_name << "' already exists" << std::endl;
@@ -190,7 +190,7 @@ void Branch::CreateMapping(const Branch* other, std::string branch_name_prefix)
 
   std::cout << "New cached mapping " << other->config_.GetName() << " --> " << config_.GetName() << std::endl;
   FieldsMapping fields_mapping;
-  for (auto& field_name_other : other->GetFieldNames()) {
+  for (const auto& field_name_other : other->GetFieldNames()) {
     std::string field_name_target = branch_name_prefix + field_name_other;
     if (!config_.HasField(field_name_target)) { continue; }
     fields_mapping.field_pairs.emplace_back(other->GetField(field_name_other), GetField(field_name_target));
@@ -208,7 +208,7 @@ void Branch::UpdateConfigHash() {
 std::vector<std::string> Branch::GetFieldNames() const {
   std::vector<std::string> result;
   auto fill_vector_from_map = [&result](const std::map<std::string, ConfigElement>& fields_map) -> void {
-    for (auto& element : fields_map) {
+    for (const auto& element : fields_map) {
       result.push_back(element.first);
     }
   };
diff --git a/infra/BranchChannel.cpp b/infra/BranchChannel.cpp
index 01856cde..a1701f44 100644
--- a/infra/BranchChannel.cpp
+++ b/infra/BranchChannel.cpp
@@ -35,7 +35,7 @@ void BranchChannel::CopyContent(const BranchChannel& other, std::string branch_n
   /* Eval mapping */
   const auto& field_pairs = mapping_it->second.field_pairs;
 
-  for (auto& field_pair /* src : dst */ : field_pairs) {
+  for (const auto& field_pair /* src : dst */ : field_pairs) {
     this->SetValue(field_pair.second, other.Value(field_pair.first));
   }
 }
diff --git a/infra/BranchHashHelper.hpp b/infra/BranchHashHelper.hpp
index 1e9c5b61..7a13012f 100644
--- a/infra/BranchHashHelper.hpp
+++ b/infra/BranchHashHelper.hpp
@@ -19,7 +19,7 @@ inline std::size_t BranchConfigHasher(const AnalysisTree::BranchConfig& config)
   hash_combine(hash, static_cast<AnalysisTree::ShortInt_t>(config.GetType()));
 
   auto hash_fields = [&hash](const std::map<std::string, AnalysisTree::ConfigElement>& fields_map, Type field_type) {
-    for (auto& field : fields_map) {
+    for (const auto& field : fields_map) {
       hash_combine(hash, field.first, field.second.id_, static_cast<AnalysisTree::ShortInt_t>(field_type));
     }
   };
diff --git a/infra/Chain.cpp b/infra/Chain.cpp
index d31dfd16..5ab1dea0 100644
--- a/infra/Chain.cpp
+++ b/infra/Chain.cpp
@@ -113,7 +113,7 @@ void Chain::InitPointersToBranches(std::set<std::string> names) {
     if (CheckBranchExistence(branch.first) == 1)
       ANALYSISTREE_UTILS_VISIT(set_branch_address_struct(this, branch.first), branch.second);
     else if (CheckBranchExistence(branch.first) == 2)
-      ANALYSISTREE_UTILS_VISIT(set_branch_address_struct(this, (branch.first + ".").c_str()), branch.second);
+      ANALYSISTREE_UTILS_VISIT(set_branch_address_struct(this, branch.first + "."), branch.second);
     else
       throw std::runtime_error("AnalysisTree::InitPointersToBranches - Branch " + branch.first + " does not exist");
   }
@@ -225,7 +225,7 @@ std::vector<TChain*> Chain::GetTChains() {
 int Chain::CheckBranchExistence(const std::string& branchname) {
   auto v_chains = this->GetTChains();
 
-  for (auto& ch : v_chains) {
+  for (const auto& ch : v_chains) {
     auto* lob = ch->GetListOfBranches();
     const int Nbranches = lob->GetEntries();
     for (int i = 0; i < Nbranches; i++) {
diff --git a/infra/Cuts.cpp b/infra/Cuts.cpp
index 1a209336..9692024a 100644
--- a/infra/Cuts.cpp
+++ b/infra/Cuts.cpp
@@ -83,7 +83,7 @@ void Cuts::AddCut(const SimpleCut& cut) {
 }
 
 void Cuts::AddCuts(const std::vector<SimpleCut>& cuts) {
-  for (auto& cut : cuts) {
+  for (const auto& cut : cuts) {
     AddCut(cut);
   }
 }
diff --git a/infra/HelperFunctions.hpp b/infra/HelperFunctions.hpp
index 996a0d13..800c5b71 100644
--- a/infra/HelperFunctions.hpp
+++ b/infra/HelperFunctions.hpp
@@ -3,6 +3,8 @@
 
 #include "SimpleCut.hpp"
 
+#include <TFile.h>
+
 #include <sstream>
 #include <string>
 #include <vector>
@@ -101,5 +103,14 @@ inline std::vector<T> MergeVectors(const std::vector<T>& vec1, const std::vector
   return MergeVectors(vec1, MergeVectors(vec2, args...));
 }
 
+template<typename T>
+inline T* GetObjectWithNullptrCheck(TFile* fileIn, const std::string& objectName) {
+  T* ptr = fileIn->Get<T>(objectName.c_str());
+  if (ptr == nullptr) {
+    throw std::runtime_error("HelperFunctions::GetObjectWithNullptrCheck() - object " + objectName + " in file " + fileIn->GetName() + " is missing");
+  }
+  return ptr;
+}
+
 }// namespace HelperFunctions
 #endif// ANALYSISTREE_INFRA_HELPER_FUNCTIONS_HPP
diff --git a/infra/PlainTreeFiller.cpp b/infra/PlainTreeFiller.cpp
index 10c4e1dd..f87f37d0 100644
--- a/infra/PlainTreeFiller.cpp
+++ b/infra/PlainTreeFiller.cpp
@@ -19,7 +19,7 @@ void PlainTreeFiller::SetFieldsToIgnore(const std::vector<std::string>& fields_t
   if (branch_name_.empty()) {
     throw std::runtime_error("PlainTreeFiller::SetFieldsToIgnore() must be called after PlainTreeFiller::AddBranch()\n");
   }
-  for (auto& fti : fields_to_ignore) {
+  for (const auto& fti : fields_to_ignore) {
     fields_to_ignore_.emplace_back((branch_name_ + "." + fti).c_str());
   }
 }
@@ -28,19 +28,48 @@ void PlainTreeFiller::SetFieldsToPreserve(const std::vector<std::string>& fields
   if (branch_name_.empty()) {
     throw std::runtime_error("PlainTreeFiller::SetFieldsToPreserve() must be called after PlainTreeFiller::AddBranch()\n");
   }
-  for (auto& fti : fields_to_preserve) {
+  for (const auto& fti : fields_to_preserve) {
     fields_to_preserve_.emplace_back((branch_name_ + "." + fti).c_str());
   }
 }
 
+void PlainTreeFiller::SetFieldsToRename(const std::vector<std::pair<std::string, std::string>>& fields_to_rename) {
+  if (branch_name_.empty()) {
+    throw std::runtime_error("PlainTreeFiller::SetFieldsToRename() must be called after PlainTreeFiller::AddBranch()\n");
+  }
+  for (const auto& ftr : fields_to_rename) {
+    fields_to_rename_.emplace((branch_name_ + "." + ftr.first).c_str(), (branch_name_ + "." + ftr.second).c_str());
+  }
+}
+
+void PlainTreeFiller::CheckIgnorePreserveRenameFields(const std::vector<std::string>& leafNames) const {
+  for (const auto& fti : fields_to_ignore_) {
+    if (std::find(leafNames.begin(), leafNames.end(), fti) == leafNames.end()) {
+      std::cout << "WARNING PlainTreeFiller::CheckIgnorePreserveRenameFields(): field " << fti << " is set to be ignored, but it is absent among input fields\n";
+    }
+  }
+
+  for (const auto& ftp : fields_to_preserve_) {
+    if (std::find(leafNames.begin(), leafNames.end(), ftp) == leafNames.end()) {
+      std::cout << "WARNING PlainTreeFiller::CheckIgnorePreserveRenameFields(): field " << ftp << " is set to be preserved, but it is absent among input fields\n";
+    }
+  }
+
+  for (const auto& ftr : fields_to_rename_) {
+    if (std::find(leafNames.begin(), leafNames.end(), ftr.first) == leafNames.end()) {
+      std::cout << "WARNING PlainTreeFiller::CheckIgnorePreserveRenameFields(): field " << ftr.first << " is set to be renamed, but it is absent among input fields\n";
+    }
+  }
+}
+
 void PlainTreeFiller::Init() {
   if (is_ignore_defual_fields_) {
     std::vector<std::string> defaultFieldsNames;
     auto mapF = config_->GetBranchConfig(branch_name_).GetMap<float>();
     auto mapI = config_->GetBranchConfig(branch_name_).GetMap<int>();
     auto mapB = config_->GetBranchConfig(branch_name_).GetMap<bool>();
-    for (auto& m : {mapF, mapI, mapB}) {
-      for (auto& me : m) {
+    for (const auto& m : {mapF, mapI, mapB}) {
+      for (const auto& me : m) {
         if (me.second.id_ < 0) defaultFieldsNames.emplace_back(me.first);
       }
     }
@@ -79,23 +108,32 @@ void PlainTreeFiller::Init() {
 
   if (vars_.size() != vars.size()) throw std::runtime_error("PlainTreeFiller::Init(): vars_.size() != vars.size()");
 
+  std::vector<std::string> leafNames;
+  for (int iVar = 0, nVars = vars.size(); iVar < nVars; ++iVar) {
+    leafNames.emplace_back(vars[iVar].GetName());
+  }
+  CheckIgnorePreserveRenameFields(leafNames);
+
   file_ = TFile::Open(file_name_.c_str(), "recreate");
   plain_tree_ = new TTree(tree_name_.c_str(), "Plain Tree");
   plain_tree_->SetAutoSave(0);
-  for (size_t i = 0; i < vars.size(); ++i) {
-    std::string leaf_name = vars[i].GetName();
+  for (int iLeaf = 0, nLeafs = leafNames.size(); iLeaf < nLeafs; ++iLeaf) {
+    std::string leaf_name = leafNames.at(iLeaf);
     if (!fields_to_ignore_.empty() && std::find(fields_to_ignore_.begin(), fields_to_ignore_.end(), leaf_name) != fields_to_ignore_.end()) continue;
     if (!fields_to_preserve_.empty() && std::find(fields_to_preserve_.begin(), fields_to_preserve_.end(), leaf_name) == fields_to_preserve_.end()) continue;
+    if (!fields_to_rename_.empty() && fields_to_rename_.find(leaf_name) != fields_to_rename_.end()) {
+      leaf_name = fields_to_rename_.at(leaf_name);
+    }
     if (!is_prepend_leaves_with_branchname_) leaf_name.erase(0, branch_name_.size() + 1);
     std::replace(leaf_name.begin(), leaf_name.end(), '.', '_');
-    if (vars_.at(i).type_ == Types::kFloat) plain_tree_->Branch(leaf_name.c_str(), &vars_.at(i).float_, Form("%s/F", leaf_name.c_str()));
-    else if (vars_.at(i).type_ == Types::kInteger)
-      plain_tree_->Branch(leaf_name.c_str(), &vars_.at(i).int_, Form("%s/I", leaf_name.c_str()));
-    else if (vars_.at(i).type_ == Types::kBool)
-      plain_tree_->Branch(leaf_name.c_str(), &vars_.at(i).bool_, Form("%s/O", leaf_name.c_str()));
+    if (vars_.at(iLeaf).type_ == Types::kFloat) plain_tree_->Branch(leaf_name.c_str(), &vars_.at(iLeaf).float_, Form("%s/F", leaf_name.c_str()));
+    else if (vars_.at(iLeaf).type_ == Types::kInteger)
+      plain_tree_->Branch(leaf_name.c_str(), &vars_.at(iLeaf).int_, Form("%s/I", leaf_name.c_str()));
+    else if (vars_.at(iLeaf).type_ == Types::kBool)
+      plain_tree_->Branch(leaf_name.c_str(), &vars_.at(iLeaf).bool_, Form("%s/O", leaf_name.c_str()));
   }
 
-  for (auto& cm : cuts_map_) {
+  for (const auto& cm : cuts_map_) {
     if (cm.second != nullptr) {
       cm.second->Init(*(TaskManager::GetInstance()->GetChain()->GetConfiguration()));
     }
diff --git a/infra/PlainTreeFiller.hpp b/infra/PlainTreeFiller.hpp
index fb96afd4..c2e0b7d7 100644
--- a/infra/PlainTreeFiller.hpp
+++ b/infra/PlainTreeFiller.hpp
@@ -36,11 +36,14 @@ class PlainTreeFiller : public AnalysisTask {
 
   void SetFieldsToIgnore(const std::vector<std::string>& fields_to_ignore);
   void SetFieldsToPreserve(const std::vector<std::string>& fields_to_preserve);
+  void SetFieldsToRename(const std::vector<std::pair<std::string, std::string>>& fields_to_rename);
 
   void SetIsIgnoreDefaultFields(bool is = true) { is_ignore_defual_fields_ = is; }
   void SetIsPrependLeavesWithBranchName(bool is = true) { is_prepend_leaves_with_branchname_ = is; }
 
  protected:
+  void CheckIgnorePreserveRenameFields(const std::vector<std::string>& leafNames) const;
+
   TFile* file_{nullptr};
   TTree* plain_tree_{nullptr};
 
@@ -51,6 +54,7 @@ class PlainTreeFiller : public AnalysisTask {
   std::vector<FIB> vars_;
   std::vector<std::string> fields_to_ignore_{};
   std::vector<std::string> fields_to_preserve_{};
+  std::map<std::string, std::string> fields_to_rename_{};
 
   bool is_ignore_defual_fields_{false};
   bool is_prepend_leaves_with_branchname_{true};
diff --git a/infra/SimpleCut.hpp b/infra/SimpleCut.hpp
index 5adbdd25..9b00481b 100644
--- a/infra/SimpleCut.hpp
+++ b/infra/SimpleCut.hpp
@@ -46,7 +46,7 @@ class SimpleCut {
 
   SimpleCut(const std::vector<Variable>& vars, std::function<bool(std::vector<double>&)> lambda, std::string title = "") : title_(std::move(title)),
                                                                                                                            lambda_(std::move(lambda)) {
-    for (auto& var : vars) {
+    for (const auto& var : vars) {
       vars_.emplace_back(var);
     }
     FillBranchNames();
diff --git a/infra/TaskManager.cpp b/infra/TaskManager.cpp
index 511158ec..76f46217 100644
--- a/infra/TaskManager.cpp
+++ b/infra/TaskManager.cpp
@@ -74,12 +74,12 @@ void TaskManager::InitOutChain() {
     assert(configuration_ && data_header_ && chain_);// input should exist
     configuration_ = chain_->CloneConfiguration();
     *(data_header_) = *(chain_->GetDataHeader());
-    for (auto& brex : branches_exclude_) {
+    for (const auto& brex : branches_exclude_) {
       if (chain_->CheckBranchExistence(brex) == 1) {
         throw std::runtime_error("AnalysisTree::TaskManager::InitOutChain - Tree in the input file does not support selective cloning");
       }
       chain_->SetBranchStatus((brex + ".*").c_str(), false);
-      for (auto& maex : configuration_->GetMatchesOfBranch(brex)) {
+      for (const auto& maex : configuration_->GetMatchesOfBranch(brex)) {
         chain_->SetBranchStatus((maex + ".*").c_str(), false);
       }
       configuration_->RemoveBranchConfig(brex);
@@ -93,12 +93,18 @@ void TaskManager::InitOutChain() {
 }
 
 void TaskManager::Run(long long nEvents) {
+  if (chain_->GetEntries() > 0) {
+    nEvents = nEvents < 0 || nEvents > chain_->GetEntries() ? chain_->GetEntries() : nEvents;
+  }
+  Run(0, nEvents);
+}
 
+void TaskManager::Run(long long nEventFrom, long long nEvents) {
   std::cout << "AnalysisTree::Manager::Run" << std::endl;
   auto start = std::chrono::system_clock::now();
 
-  if (chain_->GetEntries() > 0) {
-    nEvents = nEvents < 0 || nEvents > chain_->GetEntries() ? chain_->GetEntries() : nEvents;
+  if (nEventFrom + nEvents > chain_->GetEntries() && chain_->GetEntries() > 0) {
+    throw std::runtime_error("TaskManager::Run() - nEventFrom + nEvents > chain_->GetEntries()");
   }
 
   if (verbosity_frequency_ > 0) {
@@ -107,7 +113,7 @@ void TaskManager::Run(long long nEvents) {
     verbosity_period_ = static_cast<int>(std::pow(10, vPlog));
   }
 
-  for (long long iEvent = 0; iEvent < nEvents; ++iEvent) {
+  for (long long iEvent = nEventFrom; iEvent < nEventFrom + nEvents; ++iEvent) {
     if (verbosity_period_ > 0 && iEvent % verbosity_period_ == 0) {
       std::cout << "Event no " << iEvent << "\n";
     }
diff --git a/infra/TaskManager.hpp b/infra/TaskManager.hpp
index 59479353..83432e8b 100644
--- a/infra/TaskManager.hpp
+++ b/infra/TaskManager.hpp
@@ -55,7 +55,8 @@ class TaskManager {
   * Initialization in case of only creating AnalysisTree
   */
   virtual void Init();
-  virtual void Run(long long nEvents = -1);
+  void Run(long long nEventFrom, long long nEvents);
+  void Run(long long nEvents = -1);
   virtual void Finish();
 
   void AddTask(Task* task) { tasks_.emplace_back(task); }