Eleventh Doctor-Mr Clever chess match

The Eleventh Doctor-Mr Clever chess match was a game of chess between the Eleventh Doctor and Mr Clever, a Cyber-Planner that had taken over 49.881% of the Doctor's mind. The pair were playing to decide who would gain the right to 0.238% of the brain that remained unoccupied by either of them. The game ultimately ended inconclusively, as the Doctor fried Mr Clever from his system using a hand pulse. (TV: Nightmare in Silver)

Origins
When encountering the Cybermen at Hedgewick's World of Wonders, the Eleventh Doctor became infested by Cybermites that tried to convert him. However, his Time Lord brain proved too strong for the Cyber-Planner, dubbing itself "Mr Clever" to completely take over. The Doctor employed a mental block to hold back Mr Clever from further probing. The Doctor also professed he could regenerate and use the energy from the process to destroy Mr Clever. Stalemated, the pair decided to play a game of chess to decide who could control the last portion of the Doctor's mind and subsequently the whole body. (TV: Nightmare in Silver)

The game
The Eleventh Doctor started off on the weaker end with Mr Clever gaining an early lead. However, the Doctor brushed him off, citing they were only getting started. Mr Clever taunted the Doctor how there was no way he could win. The Doctor taunted back and proceeded to use his next move to put a golden ticket over his face to disrupt Mr Clever's circuits, granting him temporary control again, until Mr Clever finished working a patch to grant immunity to gold.

The Doctor took the chess set to Clara Oswald, who had commandeered the local punishment platoon to mount a defense against incoming Cybermen. Tied up, the Doctor removed the gold plate and they resumed their game.

However, the Doctor remained on the losing end for the majority of the game. He held on but Mr Clever deemed the game unwinnable for him, citing his queen was his only chance. Regardless, the Doctor made a deal to sacrifice his queen in return for the children's minds, Artie and Angie Maitland, to be freed from the Cyber-Planner's control. Mocking the Doctor for being a fool, Mr Clever did as requested. However, the Doctor retorted he could now win the game in three moves. Mr Clever, confused by his claims, shut down the nearby Cybermen to process if it were possible. Before he could though, the Doctor admitted the three moves he meant were not about the game, but defeating Mr Clever. Using his sonic screwdriver to amplify a nearby hand pulse, the Doctor used the device to destroy Mr Clever, ending the game with no outcome, but with the Doctor back in control of his mind. (TV: Nightmare in Silver)

Aftermath
With Mr Clever defeated, the Eleventh Doctor and Clara fled the planet with the children shortly before it was destroyed, taking the rest of the Cybermen with it. (TV: Nightmare in Silver)