Re: How to counter someone lunging in?
I'm no expert, but what's worked for me in the past is just throwing jabs as they try to come in, sometimes holding my ground or sometimes while taking a step back. This usually results in a) I hit them before they can hit me, b) we hit each other at the same time, or c) neither of us lands a punch but just throwing the jab stops them from lunging in. Ducking as they lunge with the jab and throwing a jab of my own to the body has also worked for me. My coach told me to throw a left hook while pivoting clockwise as they come in, but I've yet to try that. I'm sure others will have some better advice.
If I were to spar a guy who likes to lunge in with lead left hooks (assuming both are orthodox), I might try to time his hooks and bob/weave under it and come up with a right hook. Easier said than done though.