Pogonina vs Chess.com Move 21. ...
I got a little disappointed about Rc7 I don't believe in it. But it may be ok if one looks a bit deeper. Anyway some excerpts from the game forum about traps and matemathics.
"It wasn't really a tie, but it was very close indeed. With 911 votes cast total (the lowest number we've had so far in the game), each 0.5% (the margin of error in the percentages) represents 4-5 votes, so Rc7 won by anywhere between 1-4 votes. Still, that's quite small, given that the final tally was around 294:291 votes in favor of Rc7.
At least, this was a pleasant choice, since neither option was a blunder on our part.
Let's move on now! " (valentin)
"valentin, what a strange mathematical reasoning. The resolving of the tie is maybe due to the first vote rule. That can not be omitted. My only guess is that you were not aware of that rule. Had it not been in effect I think you are right.
So basically, it can be a totally even tie, like 292-292, but since the first vote of the two was put on Rc7, it wins." (Balticknight) - no answer.
"I expect 21 a5, inviting ...Qxc2. Will the many "drive-by" voters notice it costs our Q for R+N+P after 22 Qa3, under unfavorable circumstances for that trade?
"Estragon, material is even after the so called "trap", that is 21.a3 Qxc2 22.Qa3. What are the gains for White? Variations please!" (Balticknight)
"BalticKnight, if you believed Estragon may have been wrong, a few seconds with the analysis board would have been more sensible than an unnecessary post here. Most people discussing the game are aware of the potential trap from previous moves. In the position after Qa3, white threatens Rc1 which both traps the queen and skewers the rook behind is. Qc4 and Qc6 fail deal with either threat, and the desperate d5 doesn't work." (Elroch)
"is this seriously the way you think? It's the dumbest thing I've ever heard. I told you the strategical downside is that we can't control light squares and are stuck defending an inferior pawn structure which makes attack impossible. If you honestly believe a rook, bishop and a knight and an extra backwards pawn can outperform a queen and a bishop of the opposite color ATTACKING said backwards pawn, you need some chess 101 despite that rating of yours."
"By the way, a queen and a bishop would hold the edge in a completely pawnless game and end up slaying the knight, rook and bishop of opposite color. So your delusional "reverse advantage" won't get any better as the game progresses" (mikex22)
Your move! Or I can challenge anyone to show me a clear win for White here. (BalticKnight)
Sadly, I see no real interest in discussing more deeply various claims from several players that occupy much verbal space but seldom expose a well founded concrete analysis of a position or a question.
Well, to my knowledge, which is far below Pogonina's, only 21.c3 looks attractive. 21. a5, which according to some is a trap, is not her choice I think. There is no clear White advantage if Black chooses Qxc2.