Revert "tiny speedup with goto"

This reverts commit c8dfeb1dc07cbc39c92b9c6d20ef607ae6a9aa54.
Revert "skip IID when in check (6667715)"

This reverts commit d6f6380d8b8ee81b2b6a85101ff9bf6b36bc6f3f.

10,000 games in 10"+0.1" gave a score of 50.0%, so it's too risky to commit.