Powerful "in-between" Checks

Even the most persuasive swindles will sometimes be defeated by one artful check, as witness the following position from a game played in Iceland in 1949. Max Euwe, a former World Champion has been completely outplayed. He is behind in material and his King is fatally exposed.

White has managed to concoct an ingenious swindle. Despite his troubles, he is threatening Mate, and 1...Rxf8?? will not do because 2.Qxf8 Mate.

White's swindle is an extremely attractive one. He offers his a2 Rook as bait that can be captured with check! This check can be followed up by another check that apparently crushes White. Yet White in turn has an "in-between" check that crushes Black! here is how the swindle works:

(Notes by American Chess Legend Al Horowitz)