Left hook: hold the fist vertical or horizontal?

That is the age-old question.

Many trainers tell you to hold your left hook vertically, like you're holding a coffee mug. You can see it in the picture.

Just as many trainers say to hold it horizontally, with the palm facing down.

Which is correct?

I don't think there is a "correct" way to throw the left hook; it all comes down to your personal preferences.

If you are sport-oriented -- you always use handwraps and boxing gloves -- then holding the fist horizontally is probably OK. But if you are more interested in bare-knuckle fighting, you should probably keep the fist vertical.

Good luck finding out which variation you prefer: it's a debate that isn't going away anytime soon!