Getting That Last Little Bit...
A large percentage of people that wish to increase their vertical jumps are doing so because they want to dunk and I get a lot of people that substantially improve their VJs and are really close to dunking but not quite there yet. They can get high enough without the ball but jumping with the ball adds enough weight and changes the jump just enough that the only thing they throw down is numerous clangs off the front of the rim. Alley oops are an option but they require a lot of timing and practice.
Admittedly I had the same problem myself. The first dunk I ever threw down was a 2 handed dunk off an alley oop someone threw me off the backboard. I think I just got lucky and got the ultimate combination of an absolutely perfect throw in exactly the right spot, a runup that was perfectly timed with the throw, a great court to jump off of and great traction, and I happened to be having a REALLY good day. It felt good but it took me a year and a half after that before I got any kind of legitimate dunk in and I couldn't begin to count the frustration I experienced. But anyway, hindsight always makes things a lot simpler so here are some things I recommend YOU do if you're fairly close to getting a legitimate 1 hand runup dunk with the ball but not quite there yet.
1. How high do you really have to go?
First realize you only need to get a few inches over the rim to dunk IF your hand positioning with the ball is perfect and your takeoff angle is correct. You DON'T need to be able to palm a ball to dunk it, although it sure helps. You just have to be able to control the ball with your fingertips. When I finally got my first legitimate dunks in with the ball (1.5 years after the alley oop) what I did immediately beforehand was get on a rim that was about 7.5 feet tall and I jacked around with it trying to figure out how "low" I could actually jump and still dunk. What I determined was I only needed to be able to get my fingers over the rim if I came in at the rim at a horizontal angle (instead of straight up) and tilted the ball up out of the way on the way up so it wouldn't clang the front of the rim. Basically what I did was go up and just let the rim hit my the base of my fingers while letting the ball come up on my fingertips and down to the other side of the rim. You really only need to maintain enough control over the ball to be able to keep it somewhat still on the way up. Play around with it on a low rim and you'll know what I mean.
2. Takeoff Angle
Next, you need to look at your takeoff angle. Beginning dunkers have a habit of taking off too close to the rim. They go pretty much straight up and this means you have to get the ball up AND OVER the rim. If you approach the rim a bit more horizontally you have more margin for error. It's just like the arch on a shot. A shot from 5 feet away requires less arch than one from a foot away. So, how do you get more horizontal? Simple, take off a little further back than you normally do! Try it and see. You don't need to take off at the free throw line but just try taking off a foot or 2 back further than you normally would.
3. Optimize your approach:
Next, you need to optimize your approach. Too many people waste too much of their horizontal momentum when jumping because they spend too much time coming to a stop to gather theirselves. I like to have people separate their approach up and work on each aspect of it.
A. The Approach:
First, just work on your approach. Runup to the basket just like you're going to jump but STOP right at your takeoff point. Come to a complete stop in your "ready to jump" position, but don't jump. See what kind of position you're in. Are you off balance? Did it take you forever to come to a stop? Is most of the weight forward up on the balls of your feet or back on your heels? Next, try to "tighten up" the length of time it takes you to stop and get in your ready to jump position out of your runup. You want as little wasted motion as possible and ideally want to be accelerating the last couple of steps into your stop. Once you feel comfortable with this now try to add some more speed to it. On an ideal approach you might not be able to completely stop yourself as your forward momentum will want to carry you forward but you should still be in the perfect position to jump a split second before that happens. The basic idea is the faster you can come in while still efficiently gathering your forward momentum the higher your subsequent jump will be.
What type of approach do you use?
Some people like to get really into analyzing their final footwork on their approach. Basically there are 2 styles of 2 foot approach jumps. A step close method and a hop method. On a step close method you'll come in and your final steps will consist of the planting of one foot, than placing the other foot next to the first foot, followed by a jump. On a bounce method you'll come in and both feet will plant simultaneously, then you'll jump.
A few studies have been done comparing the 2 styles and one hasn't been found to be superior to the other, although there are slight differences. (1-3) My opinion is relatively untrained athletes and people with extremely powerful lower legs may get better results from the hop method, as it allows them shorter ground contact times and inherently tends to lessen the degree of knee and hip bend they use, which improves reactive force contribution in beginners, whose coordination usually isn't optimal. Beginners have trouble getting much reactive force contribution from their runups. The hop method does require more force to decelerate and most of the best dunkers use the step close method, or the 1,2 plant. The step close method is advantageous because it's smoother, requires less deceleration, and seems to favor faster approaches, but it also keeps your initial plant leg on the ground a bit longer. It also requires more coordination to fully optimize.
You might experiment a bit with each style to see which one you favor, just don't get in the habit of overanalyzing your steps to the point you turn into a robot. As you become more advanced and work on your approach you will likely naturally gravitate toward a step-close style of approach, but plenty of people have succeeded with either style and when put to the test neither style has proven superior. If you make a point to come in faster and smoother your body will inherently use the style most favorable for your unique physiological characteristics.
B. The Jump:
Now, back to optimizing your approach, next, go ahead and add the "jump" to your newly improved approach but make a conscious effort to come in as smooth and quiet as possible. Execute a few runups where you come in and try to make as little sound as possible. Next, go ahead and jump normally but attempt to drive off the balls of your feet as hard as you can as you leave the ground. After you've done that a few times now make a conscious effort to jump with a little bit less knee bend. When people jump with the ball they usually tend to "drop down" and bend their knees a bit more than normal. In my observations this usually hurts the jump. The conversion of horizontal momentum into vertical force is pretty much universally helped by shorter ground contact times. Exchanging knee bend for ankle drive tends to shorten your ground contact times and inherently leads to a better combo of vertical and horizontal force development, giving you a better chance at having a runup that helps your dunk, particularly the more you practice it.
In my experience VERY few people ever actively work on their approach and even fewer then that break it up into segments and work on each part individually. I would get about 8-10 quality reps each of each of the above 3 drills for at least a few sessions over the course of a couple of weeks. It shouldn't take you longer than 15 minutes or so but that is your practice.
To review, here are the steps you should take to optimize your approach.
1. Identify whether you're a "step-close" or "hop" jumper
2. Work on just your approach without the jump. Work on coming in fast and accelerating your last couple of steps
3. Add a jump, but attempt to be as quiet and smooth as possible during your last few steps, almost like your dancing
4. Remain smooth and go ahead and do a regular jump, but make a point to really drive off the balls of your feet
5. Now try to make a point to drop down a little less than normal.
4. Make your dunk attempts count!
Now the important thing: Don't immediately go and try dunking with the ball. It probably won't work because you're gonna be tired. Wait for the right time. When is the right time? In my opinion if you're one of the "close but not quite" dunking types the ONLY time you should ever jump with the ball is when you're in an environment conducive to promoting very high quality jumps. That means you need to be in competitive situations around crowds of people and get REALLY good and warmed up. Recreational full court games played once or twice a week are some of the best opportunities for newbie dunkers. Not that I expect you to dunk in a game, but the environment tends to produce adrenaline and, as you know if you read my articles, adrenaline universally helps jumping performance. This environment also tends to promote a REALLY good warm-up. In my experience 15-20 minutes of recreational basketball or something similar will typically produce a superior warmup to any cutting edge dynamic warmup you can come up with. That's not saying I don't recommend dynamic warm-ups, but that's the truth. Do a few dynamic stretches so you don't tear a hip flexor, groin, or achilles then play a game and get good and warmed up then try some dunks on the side. Some people will actually get their best jumps in a good hour after intense activity. Your mileage may vary. I also wouldn't recommend you try for dunk attempts more than twice a week. Once a week will be fine for many people.
Now a few added tips:
A. Go where the traction is
Don't waste your time trying to dunk on courts that have shitty traction. If you're a bilateral 2 foot jumper the traction of a court can make a HuGE impact on your jumps because the traction has a bigtime influence on how much speed you can carry into your runup. This means you should stay away from most outdoor courts as well as old indoor wooden courts. Their traction sux and will cost you inches on your dunk attempts.
Concrete also doesn't have any flex to it and won't give you any energy back which is why most people tend to jump slightly higher on a good wooden court. Ideally your jumps should be on relatively new and regularly maintained wooden courts with superior traction. One thing you can do to temporarily improve your traction is spit on the floor and rub your shoes in it a few times before you jump. As the spit dries your shoes will temporarily have more "grab". Play around with it and see. (And yeah I know this advice is pedantic as hell but this your first dunk we're talking about here and you don't wanna jack around).
B. Wear ankle weights in your pockets
Go to walmart and get a pair of 2.5 lb ankle weights. When you go to the gym to play your games put the ankle weights in your pockets for a game or 2 so you can get a little potentiation affect. In between games take the weights off and go throw one down.
C. Incorporate hang cleans and/or snatches
I don't necessarily think the hang clean and snatch are panaceas for vertical jump development but I definitely think they can bridge the gap between how high you jump without a ball and how you jump with one. A properly done clean or snatch is nothing more than a jump with a load in your hands and I think they help get you used to jumping while holding onto something. Jumping with a ball minimizes your arm swing. Instead of using your arms for your swing you tend to bend over a bit more and have to use more of your traps and upper back. The hang clean and snatch will both teach you to get more out of these muscles. Personally when I first learned the hang clean my vertical jump didn't go up any but my jump with the ball definitely did.
Here are a couple of videos on learning the hang snatch and hang clean:
The Jump Snatch
The Hang Clean
A simple way to incorporate those lifts to your routine is just pick one or the other and do 4-5 sets of 1-3 reps anytime you train your lower body, or do one of the lifts every other day and alternate back and forth between them.
Well hopefully this info. helps you on your quest to throw one down. If in doubt remember the one surefire cure towards an inability to dunk is to GET YOUR VERTICAL JUMP HIGHER. Continue boosting your max VJ and sooner or later you'll reach a point where coordination, holding onto the ball, slick courts, etc. are no longer an issue!
1. A Comparison of Two Landing Styles in a Two-foot Vertical Jump. Gutiérrez-Davila, Campos, Navarro
2. Coutts, K.D. (1982) Kinetic differences of two volleyball jumping
techniques. Medicine and Science in Sports and Exercise 14, 57-
3. Potential for non-contact ACL injury between step-close-jump and hop-jump
tasks. Department of Physical Education, National Dong Hwa University