-/// to be replaced later. TTEntry t1 is considered more valuable than TTEntry t2 if
-/// both are from the current search and the depth of t1 is greater than the depth of t2,
-/// or if t1 is from a previous search but its depth is at least 8 ply deeper than t2.
+/// to be replaced later. The replace value of an entry is calculated as its depth
+/// minus 8 times its relative age. TTEntry t1 is considered more valuable than
+/// TTEntry t2 if its replace value is greater than that of t2.