In which I play "King of the Ring", published by Gremlin Graphics in 1985. This one was programmed by John Tometzki.
It took me a little while to figure out what was going on. This is purely a simulation game. You take the role of the trainer of a (presumably) young boxer, choose what sort of training they will pursue between fights, and pick their opponents from a stable of 20 boxers in the league. In between rounds of each fight, you choose what type of instructions to have your fighter focus on. The fights themselves are simulated; there is no controlling of your boxer (the purple one, on the left, by the way).
I think this might be interesting if you were very keen on the sport of boxing and thought that you might make a good trainer.