I remember your explanation and I still don't know for sure how much is demanded aerobically and how much is anaerobically in a typical game.
The basketball numbers that I am using are 60/20/20 alactic, lactic, aerobic. These are from a pretty classic SSC book and I believe the numbers were arrived at using college basketball players who played continuous full court basketball (a scrimmage) wearing monitors. Play stopped for out of bounds, fouls, etc, BUT there were no time outs, no time on the bench, no quarter-time, etc, so if anything an actual game is less aerobically demanding. Pick up basketball is probably even less at least here where players argue and re-check the ball constantly.
I have my doubts, because i struggle to dunk in games even when it become effortless for me to dunk in practice. It could be like you explained that you need the right groove and runup and since in games you're not given what you want but rather have to work with the space available to you, i'm not able to hit my usual positions to do it properly? I can buy that in principle. But i was dunking routinely around the rim from all angles then. That's why i'm pinpointing my lack of aerobic fitness because that could be a possible weak point.
I get that you think that someone who dunks from all angles should perhaps struggle less to dunk in games. Even if you don't buy my explanation, you are pinpointing it on something that cannot be the reason! You also have small biceps... but why not pinpoint your lack of in-game dunking on your weak biceps? Aerobic fitness is NOT the reason why you struggle to dunk in games! You have to think about basic physiology. Having a well conditioned aerobic energy system will allow you to do sub-max (FAR submax) work continuously. A more fit aerobic system will be able to fuel a higher difficultly of work but nothing close to dunking. You can argue about the aerobic/anaerobic %'s in basketball but if you use a sport where the numbers are more exact you can see just how poor the aerobic system as far as maximal effort. No matter how fit you are the aerobic system kicks in at around 30s of sustained work. Not surprisingly, sprint speed drops off precipitously after 30s. Usain Bolt can run 300m in 30.9 seconds (an average of about 10.3 seconds per 100m). His best 400m time is 45.5 seconds. The time required to add that last 100m is 14 seconds! Someone with less aerobic fitness might run with even worse ratios... say 15-16 seconds. The GOAT at the 400m (Michael Johnson) could run his 400m only 13 seconds worse than his best 300m. That's the aerobic system of the greatest long sprinter in history.... And his added time over 100m is what you would expect out of a high school girl....
The point is that the aerobic system is a low intensity system. Having aerobic fitness will help you as a basketball player because you will be able to jog up and down the court without being the last one down. But when you go to dunk you better have the ATP ready to fire those non-oxidatitive fibers. That ATP is refilled during extremely low intensity periods, eg standing around on the court... possibly walking. You can take the fittest man in the world and if you have him run two miles at a pace that challenged him and then ask him to jump as high as possible 10 steps before he crosses the line.... he will struggle as much as you.
Even if you're right about basketball being mainly anaerobic, i think my aerobic ability is far below average to the point it will drastically affect my performance on the court. I don't think i would do well in any meaningful test (eg the one LBSS suggested or the ones you have offered). I think you're perhaps under-estimating my lack of fitness. I'm prob one of the least fittest members of this site, including raptor who has chronic problems with fitness. For me it's been from an intentional neglect to focus on pushing my lifts up which are slowly coming around to where i'd like them. In the summer when I was lean, i dont know if i was actually fit, or it was just easier to move around being so light.
I'm not doubting that your in absolutely terrible shape!! ( Although I do call BS on you being 25% bodyfat - being able to dunk at 25% bf even at your height would be a major accomplishment ). I'm also not arguing that your horrible aerobic fitness doesn't detract from your ability to play good team basketball. If there is a long period in the game without a dead-ball and you find yourself quickly becoming the last one back on offense/defense because your walking while everyone else is jogging... Then your lack of aerobic fitness is hurting the team. My argument is that your examples don't illustrate a lack of aerobic fitness (not being able to play good on-ball defense, not rising on your jump-shot and not being able to get in game dunks because all those examples suggest a lack of anaerobic conditioning, a lack of mechanical proficiency, and the unfortunate effect of specialization***.)
However, despite the fact that aerobic fitness may be a weak point in your game.... I still don't suggest that use sustained cardio as the means to bring it up. Sprint intervals CAN be useful for someone like you because they will provide a lot of bang for the buck as far as bodyfat goes AND there is something psychological about getting used to sprinting 60-100m repeatedly that makes a basketball court seem REALLY short. However, I still recommend you improve the bulk of your fitness with more basketball specificity.
The best argument I can give you for this is anecdotal... The year after college I didn't run track at all but I did play a lot of basketball.... we played pickup ball 4-5 times a week and would play upwards of 8 games on a good day. I was in amazing basketball shape and could dunk the ball off a drop step... I still rarely dunked in games unless it was a put back or a truly clear fast-break because dunking in games is HARD... but I digress.... The point was that I was one of the fastest and fittest guys on a court shared by a lot of high-level basketball players. Simply from playing basketball a lot and having an athletic background. Years later I didn't have a good pickup basketball resource and got back into running and at the seasons end I was in pretty decent track shape and pretty good aerobic shape (I'm talking 50 second quarter mile, 2:10 in the 800m, and the ability to run a 5 min mile - levels that are probably above where you are shooting for). However, when I played a game in a summer league my friend had organized I was gassed pretty quickly. Sure, I was still doing better than the weekend warrior's who were in terrible shape. But my basketball fitness wasn't anywhere near the level it was at when I actually played a lot of basketball. Basketball fitness is really specific. While I stand by the fact that it's primarily anaerobic it's also just simply unique. There really is not substitute to playing basketball for you.... if you don't have a good resource to pickup or league basketball.... Then I would stick with the basketball drill I gave you AND others that you can make up. They won't be as good as playing but they will be a close second. Keep it simple and keep in measurable. Another good one: how many times can you dunk in 2 minutes given that you have to dunk on alternating hoops? That will help your in game dunks way more than any cardio...
I am glad you made this point because it's something i've noticed before. I find in traffic it's harder to dip down into a jump (even a quarter one) for a SVJ or RVJ off a few steps. I wonder if there is benefit in training partial exercises like heavy quarter squats to improve ones ability to jump with a less knee flexion. It would be more useful to me for dunking in games..
Sorry, like LBSS said... GPP man. Full and quarter squats are GPP. Neither is executed at anything near the speed of a jump and neither involves similar mechanics. You have made some good strides in your athleticism and used squats... Don't go overboard now and think that you can weight lift yourself to gains in every reactive motion.... Your better off learning to dunk off different plants. Better to analyze your jump and find out how to get better at in game dunks. My problem with in-game dunks was always that my dunks were restricted to one footed dunks or put back dunks because although I jump well off two feet I use a left right plant which would be great if I am left handed (or could jump high enough to do a 360) but I am not.
***One last point about specialization. You should not underestimate the unfortunate lack of carry over that happens when you become a specialist. You have put a lot of work into your squat... If you take someone who hardly squats and he has similar bw to squat ratios... He will almost always be faster/stronger/etc. Getting good at something unfortunately means it starts to provide less aid in similar movements. You are now a specialized squatter and jumper. So your 34 inch jump (or whatever your PR is) will translate to a lot less when you have to jump at an odd angle, weird plant , in traffic, or simply without the mental queuing that you have learned to do before you jump in practice... Your old 25 inch jump translated a lot better because you hadn't yet reached a level of specialization... The guy who had trained his vertical from 15 to 25 inches probably saw your 25 inch jump and wondered why he couldn't use his 25 inch jump to rise up on his shot, block shots, etc. It's an unfortunate thing that happens when we get really good at something..... but hey it's because you have finally gotten some athleticism !