if I take pawn I reach this position
15... Qxg2
( I don't take free pawn two times but It's my mistake)
at this position it's not possible white have development advatange black need avoid it example tactic
r4rk1/pp2bpp1/2p1pn1p/4N2P/3P4/8/PPPBQPq1/1K1R3R w - - 0 1
not possible Qxg2