I'll do one-two and one-two-three combos on the bag and I've noticed that I'm hitting with my middle two knuckles instead of the first two. I forgot to ask my instructor, but is there anything I can do or do I just need to work on technique.

Adjust fire.

I would say that if it's not hurting you, there is no problem. Do you work the bag with gloves or not? I have found that when I work no-gloves, I have to be very careful about hitting with the first and second knuckles. I bruise the third one pretty easy.

I use no gloves when i practice them, nor do my wrists hurt from the work; I think it may be because I keep my wrist tight and maybe also because I don't punch perfectly horizontal. The thing is when I first start punching, I'ts with the first two, but after a few seconds, it drifts to the middle two. An extra question to throw into the mix, should my punches be perfectly horizontal, or turned slightly?

Hello

Are you hooking the combinations? Punching upward? I agree with Matt probably not a ~major problem~ just an interesting mystery...

Jeff

All straight punches, with an occasional hook.

A question: When you punch, are you punching the centerline of the bag, or slightly to either side?

As close to the middle as I can, but some shots inevitably go to the side a little.

I'd say keep working on your technique until every punch is the same, with the first two knuckles. When you adjust your wrist to punch with only them, the knuckles will align with the bone in your forearm, thus reinforcing the punch and making it stronger. Plus they protrude more than any other knuckles and will deliver more pain to your opponent.

AND, you always want to make sure that when you are doing repetitions of the same technique, each one of them is the same as the last. You want to be able to rely on your technique.