

The big competition of the weekend was the US Collegiate Final Four. Not the basketball-related office-gambling-pool event which also goes by that name, but the team chess tournament where the top four teams from the Pan-Ams in December 2015 compete in a round robin to determine the National Champions.
This year's Final Four was held at the Marshall Chess Club in Manhattan, April 2-3, between:
Webster/SPICE(6 GMs, 2734 USCF avg.)
Texas Tech (3GMs, 2 IMs, 1 WIM)
University of Texas, Rio Grande (4GMs, 2628 USCF)
Columbia (1 IM, 1 FM)
Strangely, Webster entered as the defending champions, but they did so despite finishing outside the top 4 at the 2015 Pan Ams. This was because the Webster B team finished in the top 4, which allowed Webster to send one team to the Final Four, and they chose to send their "A" team instead. Hard luck for the B team, but hard to argue with the players they chose -- GM Le Quang Liem, GM Illya Nyzhnyk, GM Aleksandr Shimanov, GM Ray Robson -- or their result: Champions for the fourth year in a row.
Canadian GM Anton Kovalyov was board 1 for UT Rio Grande. He lost twice, once against a brilliant technical game by the top-rated player Le Quang Liem, and once in a huge upset in the last round to IM Arthur Shen from Columbia. Our tactic comes from his first round game vs GM Yaroslav Zherebukh. Kovalyov has just played 27...Nb4 attacking the Ra2. His opponent did not find the best defence in this very complicated position. Can you?
Hint:
Solution: see the game below.