A lot of improving your 225 for reps is technique. Doing it powerlifter style where you get a big back arch, wide grip, and keep your elbows in while minimizing your range of motion helps a lot. It puts the onus heavily on triceps (and some on front delts) though, so it's not good for bodybuilding but it's effective for improving your reps.
In getting ready for pro day I trained to lift like that and went from 18 to 28 reps at 235# bw without significantly improving my strength.
Now, though, I can lift far more reps than that but lift it bb style with flared elbows but am just stronger haha. I did a drop set from 405 the other day where I finished up with 18 reps at 225 after 10 and 12 reps at 4/3 plates.
Some ppl put up ridic #s. Dri archer this year got 20 reps at 173, Thomas brown in 2008 may have been the strongest player in the nfl pound for pound put up 25 reps at 180. I think he could have done more if he'd trained for that lift too, that guy could bench 500 lb at 180.