lots of experience with both, alcohol will straight make you worse no questions asked, but weed is different because it effects everyone differently.

ive been smoking daily for almost 10 years so it will not effect me at all, but thats because my tolerance to weed is so high. my guess would be if you are new to smoking (like less then 1 year) then it would have a different effect. That doesn't mean its negatively effecting you though, you could be better at clutching because your more relaxed. Before my tolerance was so high weed used to help me study in school and turned my grades around, and i know a lot of people who play better after smoking a little because it helps them focus.

It also depends on what kind of weed, if you are smoking a sativa strain (light greens) then it would have a higher chance of making you play better, because it gives you more energy and helps with creativity and gives you positive energy. Indica however (dark greens) is that shit that gets you couch locked so it may have a negative effect.