411 REFERENCE · Wikibooks
Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Ba4/4...Nf6/5. O-O/5...Nxe4/6. d4/6...exd4/7. Re1/7...d5/8. Nxd4/8...Bd6
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Ruy Lopez:Riga Variation rd bd qd kd rd pd pd pd pd pd pd nd bd pd bl nl nd pl pl pl pl pl pl rl nl bl ql rl kl
Ruy Lopez:Riga Variation
With her last move White created the dual threats Nxc6 (bxc6 Bxc6+ winning the exchange) and f3. Can either of these still be played?
It turns out that 9. f3 allows perpetual check, as it removes the option of driving away a Black queen from h4 by playing g3.
9. Nxc6 it is, then.
References
Ruy Lopez