-/// Stores the endgame evaluation functions maps. Should be per thread
-/// because STL is not thread safe and locks are expensive.
+/// EndgameFunctions class stores the endgame evaluation functions std::map.
+/// Because STL library is not thread safe even for read access, the maps,
+/// although with identical content, are replicated for each thread. This
+/// is faster then using locks with an unique set of global maps.