diff --git a/dev/src/dev.cpp b/dev/src/dev.cpp
index c538b98dcec2753c5588697de57239e76b36a29f..889b4734328e0a7e447e11e774881c2fadc5a4fc 100644
--- a/dev/src/dev.cpp
+++ b/dev/src/dev.cpp
@@ -27,7 +27,7 @@ int main(int argc, char * argv[])
 
   config.setState(machine.getStrategy().getInitialState());
 
-  config.printForDebug(stderr);
+  std::vector<std::pair<SubConfig, Transition*>> trainingExamples;
 
   while (true)
   {
@@ -35,8 +35,10 @@ int main(int argc, char * argv[])
     if (!transition)
       util::myThrow("No transition appliable !");
 
-    fmt::print(stderr, "Transition : {}\n", transition->getName());
+    trainingExamples.emplace_back(config, transition);
+
     transition->apply(config);
+    config.addToHistory(transition->getName());
 
     auto movement = machine.getStrategy().getMovement(config, transition->getName());
     if (movement == Strategy::endMovement)
@@ -48,10 +50,10 @@ int main(int argc, char * argv[])
 
     if (config.needsUpdate())
       config.update();
-
-    config.printForDebug(stderr);
   }
 
+  trainingExamples[10000].first.printForDebug(stderr);
+
   return 0;
 }
 
diff --git a/reading_machine/include/SubConfig.hpp b/reading_machine/include/SubConfig.hpp
index 66725c8b4296c1b23bc7a3f41d4c7d7222004c4a..70f0ce589a4826259d8364e944f10de034222200 100644
--- a/reading_machine/include/SubConfig.hpp
+++ b/reading_machine/include/SubConfig.hpp
@@ -8,7 +8,7 @@ class SubConfig : public Config
 {
   private :
 
-  static constexpr std::size_t spanSize = 100;
+  static constexpr std::size_t spanSize = 50;
 
   private :