An unguided search for a good move would be inefficient here. Much better to look at every check. And your looking can be further guided by a concept: see how Black’s king is out in the open with fellow pieces behind it on the first rank and White rooks to its north and south. These conditions are favorable for a skewer if White can nudge the king onto an appropriate line. The tools he has for the purpose are one check with his rook (Re7) and two with his knight (Nd4 and Ng7). Re7+ doesn’t work; Black moves his king to f6, farther away from his other pieces, and if White tries to check again with Rf7, Black just takes the rook with his king. Nd4 loses the knight to Black’s pawn.

Ng7+, however, is another matter. Examine the squares surrounding the king and ask which are off limits. Black wouldn't be able to move his king to the f-file because White has a rook there. The seventh rank likewise would be made off limits by White’s other rook. The only option would be to move the king to d5 or d6. Either move aligns the king on the same file as its rook—its loose rook. White rushes his rook to the same file with Rd2+. The king has to move, and it can’t protect the rook because it is forbidden to enter the seventh rank. White wins Black’s rook next move.

This position is a vivid study in how a single check, carefully examined, can for all practical purposes end a game. To the untrained eye Black’s position does not look so precarious.