Ahem...

The rule is (Artice 9.3 FIDE)

"9.3


The game is drawn, upon a correct claim by the player having the move, if:


a.


he writes his move on his scoresheet and declares to the arbiter his intention to make this move, which shall result in the last 50 moves having been made by each player without the movement of any pawn and without any capture, or


b.


the last 50 consecutive moves have been made by each player without the movement of any pawn and without any capture."

In my experience most servers screen for this including RHP.