Just read this on Fight Night Blog:
There is no need to choose a blocking direction. If you or your boxer’s Reflexes are up to the task your boxer will move their arms to the right spot. This allows you to throw punches while holding down the Block, making the transition from Defense to Offensive a little quicker.


Silly me. I never thought of it from that Angle. Boxers now have a reflex rating so you can punch/block and rely on your fighters block strength/ and reflex for (probably very brief) periods of time...