A chess-punch is a strategic move between two people who are battling for control / power over a situation or others. Where the attacker uses a combination of mind-games and plausible truths to out-strategize their opponent in a grab for power, to such a great extent that it disables their component and prevents them from making any further moves. In doing so - it can create great mental anguish in the mind of the person being attacked and can lead to mental illness.
Kareem was a workplace psychopath who placed great emphasis on the power that he had over situations and others. He had a background spreading democracy throughout old Russia, crazy stories that inferred past involvement with the intelligence community, a deep understanding of how to read others and knew how to use sub-text to alter the perceptions that others had of him, themselves and the situations that they were involved in. He was a scary guy.
Dave - who was new to the business - got off on the wrong foot with Kareem. Kareem was worried that Dave was trying to disempower him. Kareem used manipulative tactics to instil fear in Dave's mind and to out-strategize him - ultimately culminating in a chess-punch that disabled Dave and prevented him from being able to function.