After the temporary rollback of ratings to recalculate rating, My Δ in Educational Codeforces Round 161 (Rated for Div. 2) changed from +50 to +40. Is this normal? Every time recalculation has happened, My Δ has either remained same or increased by +1 or +2 in all of the contests except this one. If cheaters on average perform better than their current rating, Then according to the Elo system after removing cheaters everyone should get a net increase in Δ right?