You will have your personal best grip. This could be a little wide, or a little close. It will vary from person to person. It’s just the width that feels best, and allows you to press the most weight. WHATEVER that width is, that’s your “standard.” When the big lifters talk about grip width, they are only really telling you what grip they like best.
If you bring your hands closer together than “standard” its a “close grip” bench, and will shift emphasis to the triceps.
If you moves your hands farther out, that’s a “wide grip.” This will make it harder to use the triceps and, bring more chest into the lift.
You could think of close grip bench and wide grip like assistance exercises. Lifts that you do to target a specific area of your body, or “weakness” in your main lift. Similar to dumbbell benching, or incline benching. “Standard” width benching for lower reps to build your strength, then wide grip benching for higher reps to build your pecs. Or to build power out of the bottom of your bench press.
Louie Simmons has talked about using illegal wide benches for years. Check out his article “Raw Benching.”
"I met Bill Seno; he was a bodybuilder/powerlifter, which was common in the 1970?s. Bill was a bench record holder as well. He used a close grip style, with his massive size. Bill told me to bench ultra wide (illegal grip), one inch outside of the rings. He recommended that I do a six rep max week after week, until I could go no further. At that point, he said to go eight reps until I could no longer make progress, then on to ten reps, and again to failure. At that point, he recommended returning to sixes, and repeating the cycle- going for a new record with six reps, then eight, and so on.
Did it work? It took my 340lb bench at 172lb body weight, to a 515lb bench at 212lb body weight. Warm up a lot, and make smart jumps. A 3-week wave at one weight worked best for me. Thanks, Bill."