TL;DR 1 He doesn't lefty hook very often, but he's done it a few times and it's another wrinkle in his developing post game, which is fairly far along. In fact, mostly there and in need of refinement and experience more than major additions, apart from the lefty hook as a specialty counter.
TL;DR 2 I watch a lot of Blake Griffin and like what I see. He plays a little too quickly, uses a few too many moves per possession, but he's already quite good and has MUCH more of a post game than non-Clippers fans seem to realize (as is the case with Dwight). Special offensive player, Blake.
Variety of moves? Check. Depth of counter game? Check. Athleticism? Check. Eat-the-rim attitude? Check. Solid footwork? Usually check. Doesn't care about shot-blockers? Check, goes right at them without wavering. Generally makes the right play (FGA vs pass-out, etc)? Check. Good passer? Check.
Has a really sound framework of moves. Needs to slow down, but the moves are there and the understanding of how to chain moves together against a real defender is there, and that's special, not very common at all (even less so among contemporary bigs). Needs a lot of work on his jumper and needs to be encouraged daily to keep developing that left hand, because it's a huge part of his arsenal just to have that left hook, and he's showing it. Gary Payton, I don't think I ever saw him use his left hand on a layup and it cost him at times. Dirk show-cased a lefty layup from a righty on a game-winning post shake against Bosh in 2011, helping to highlight the importance of the off-hand, and Blake is starting to show it. He has a really good understanding of change-of-direction, and at times, he shows these wonderful sequences of chained moves against a defender that frequently looks flat-footed and helpless. He does make a lot of quick decisions, but most of them are good, he just needs to tweak his tempo and he'll be devastating. A real jumper and FT shooting would be nice, but even Malone and Olajuwon struggled with that this early in their respective careers/at similar ages, so we if he works at it, it'll come. He's showing bank, he's showing the willingness to take the jumper and that's as much as you can ask for early on. Tenacious. I mope here and there below about positioning/timing/doing this, that or the other as far as getting better position, but he's already showing it more than most players. He knows how to do it and does it of his own volition, a lot, and that's also atypical. His off-ball game, critical to a post player, that's more developed than his on-ball game and that's a really good thing.
If he never crossed over between his legs again, it wouldn't be enough. Eliminating that from his game would be a REALLY good start to improving his post offense. Blake's a wicked talent with a lot to offer a team, but my God, I want to smack him in the mouth every time he does that because it never ends well and isn't a smart big play to begin with.
Don't mind when he uses glass, especially on that left-block shoulder-shimmy turnaround J he likes to use, though. He's got a couple of moves in his set that look a lot like Olajuwon staples. Probably where that damned crossover comes from, but he's not nearly as fluid, as good a ball-handler, as light on his feet or in general as skilled as Olajuwon, so that one, meh. The shoulder fake, however, is a really nice stall and he seems to be doing quite well finishing after that move. Needs to work on his face-up J, and his face-up game in general. I'd like to see him cut down on the step backs he take out of a face-up post as well.
I see Blake not getting awesome post position a lot of the time and I think it's because he doesn't understand just-in-time positioning very well. Unless you've got some epic physical advantages, you can't just expect to grab and hold position without a major mismatch. Shaq comes to mind, but someone with the lower body mass and strength of a Tim Duncan does, as do Zach Randolph, DeMarcus Cousins, Charles Barkley, etc, etc. Wide bodies, in other words. Blake isn't that. He's not skinny or anything but he's not humongous or phenomenally strong in the base, so he needs to work a little more on off-ball movement, specifically on timing his cuts to the post and maybe using the screen and roll to establish post position a little more (Dwight is really good at that, very Karl Malone-ish). You can fight in the paint and stuff, that's good, but if you do it too much, you run into turnovers and fouls, plus if you don't have the physicality for it, you get shoved out beyond 12 feet a lot and have to rely way more frequently upon your face-up game, which is never going to be as efficient as your close iso game (face-up or back-down). Anyway, it's not that he DOESN'T do this. Watching the Clippers, you can't help but notice he flashes to the post pretty well, I just think he could do it a little more, a little better. He's 23 and in his 3rd full season, there are a lot of areas where he could, and will, improve. The post requires way more thought and experience than most people realize and obviously Blake is doing very, very well already (could stand to hustle more on the boards, this year, he's slacking off some). He rub-screens a lot, especially under the foul line extended, which is good, especially because he seems to know how to use the rub screen with some timing to get himself decent post position. I'd like him to reverse-pivot into the face-up a little less and be a bit more confident in his back-down game, though. One guy he could stand to watch a little is Dirk at the elbow. He puts on a clinic of how to get a clean look in the key despite getting shoved to 14 feet wide left/right, using a couple of moves that Olajuwon loved to get fadeaways in and around 11 to 15 feet, and of course Dirk has this textbook-pretty body protection where he uses his leg and a fade to get huge separation. Blake could stand to learn a little of that, especially with a nice high release and good arc, because that's a move that Dirk's using in his mid-30s without any kind of vertical leap or serious foot speed. Well, "learn to refine" and maybe that specific version of it (wrong-foot or with Hakeem's footwork, either way), because I've seen him use a version of it when he gets into the paint, spinning to his left into the fadeaway. So maybe "adapt and expand" would be a better phrase.
Saw the lefty hook against Denver. Started with a face-up, including a needless crossover (grrr!!! anti-fundamentals) but he quickly restrained himself, backed in, gave a shoulder-shimmy to I think Koufos and put up the left hook. A little too much fade, but with refinement, that's a good move (and he made it, in any case). Same game, saw him face up a slower, taller defender and settle for a bricked long jumper on the left sideline.

Bad Blake!
Beautiful post against Scola. I'd warn against the way he always sticks his non-pivot foot out, it leaves him unbalanced a lot. You'll see what I mean after he reverse pivots some time. I know he's jab-stepping and trying to fake the jab step, but it's an unnecessary stutter that does more to ruin his move than to fake the defender, especially when he over-balances his upper body off alignment with the jabbing leg. It's begging for a travel or a bumble, the latter of which he does a lot. Anyway, drove left into the paint, pulled a beautiful spin (his best post move, regardless of the side) and totally owned Scola for the easy layup. Could stand to work on keeping the ball above his shoulders a little, but he's a young post player, so that's kind of like saying "water is wet." About the only 20-anythings I've ever seen do that well are Shaq and Duncan.
Don't ever want to see him take a fade-away hook outside of the paint again. He pulled a nice shoulder shake to get to the fade and should have made it a classic fallaway jumper. Clean that up, because the footwork underneath it was good, and that's another solid move in his arsenal. Saw him pull an up-and-under that would have left him in great position for the lefty hook, but he fought back for a contested righty shot. Made it, but over the season, that's not going to be super consistent. He's got Young Guy Syndrome; like a young guitarist focused on a ton of speedy notes, Blake's a little overzealous with the number of moves he wants to use. He plays a little quick, a little stiff/tight. The game is there, he's got the mobility, he's got the moves, he just needs to relax a bit and slow down. A lot of critics are saying when his athleticism goes, he's going to have problems, but you can see the emerging shape of his post game and I feel like he'll be (to a lesser extent, of course) a little like Hakeem, peaking from 30-32ish as his just-past-prime athleticism matches up with his developed and polished skills. He's got highly intriguing potential, and of course the raw athleticism to make it work even now.
Classic example of too many moves against the Hornets early on. Got really wicked early post position cherry picking, got the ball in DEEP post position, made a good move to the left baseline but then blew it by turning back middle (awkward angle, almost underneath the rim at the bottom of the key) and got swatted hard. He had the lefty hook with his body protecting the ball, so it would have been a foul otherwise. Hundred-dollar start, ten-cent finish. That's something that'll improve with experience, though it'd be nice to put a veteran post player on the team to work with him a little, you know? Or get a retired old guy to mentor him some.
Saw a nice running righty hook against the Hornets. Would have been happier if he'd fought a little harder for post position, though. He was floating on the left baseline, then walked straight to the pass instead of sealing and getting closer or even hop-catching to receive the ball closer to the key. Split the double, got up a nice look. Missed, but that's less relevant because it was a good move.
Awareness could improve sometimes; as I said, he plays with frantic energy and sometimes he misses easier options. Saw him against Detroit fake Maxiell right out of his socks but miss the duck-in because his head was down, so instead he missed a double-contested turnaround fade. Little stuff like that riddles his game. He makes a lot of really great first moves, though, and what that says to me is that he's taken what's often the hardest step. Getting a player to slow down sometimes doesn't even need to be coached, but it's also often the simplest thing to clean up, at least in my experience. Blake's got the starter moves, he's even got the counter moves, which saves one the effort of teaching them. He literally just needs to slow down and see more of the options that he creates for himself and just take advantage of those. A lot of people used to talk about Brook Lopez's counter-post game (or at least post fanatics like myself, anyhow), raved about his age and how he could go two, three moves deep in a measured, instinctive manner. Well, Blake can do it do, he just needs to stop playing at x16 speed and play at like x8 speed, then give someone x16 here and there. He's unpolished, but man, if he's this good now, I'm scared for the league at 26, 27.
Less thrilled when he lets guys off the hook by taking the face-up J from far out without even trying to get closer though, especially against flat-foots like Charlie V. Punish that matchup, or maybe move the ball and try to get closer; run a hand-off play and cut to the rim, for example.
Saw a nice against Maxiell. A little frustrated he didn't pull the 10-foot faceup J right away, because that was a clean look, but he did a smart thing after that; put the ball on the deck to back down, didn't like it, kicked it out, got it right back on the re-post. Love seeing that, both from the post player and from the guard. Love me some Chris Paul at the point. Then he lost the ball dicking around with it near his ankles and had to go scrambling when it was poked away, taking a fade-away J as the clock ran down, so that wasn't awesome. But the middle part was. Blake loves to get low when he faces up, which makes some sense because it gives you the greatest explosion and the sweep-through still gets you calls, especially if it's not an obvious foul-bait but part of an elbow post, but it comes with risks, and ball control declining is one of those risks. Post defenders are taught classically to TRY and keep the ball below an offensive check's waist because it's easier to control the possession that way. That's usually a little more back-down, of course, but the principle remains the same in a face-up that close to the basket.
Obviously, I love when he gets good low position, drives face-up and gets INTO the paint, because that's some kind of dunk waiting to happen. Hakeem talked about that in his training video with Dwight, among other things, and he's right: you can use spins and face-ups and drop-steps to get to a dunk from the baseline a lot, and Blake is actually quite good at this when he gets that sort of initial position. He certainly has the instinct to go to the rim, which is good, because that's hard to teach (witness exhibit A for ARRRRGH in Al Jefferson...).
Now and again, he'll flash some really quick, fluid moves chained together and you just sort of drool at his potential. Catch in the post, face up, fake baseline, spin back right, shoulder shimmy to hook, all in one smooth procession, under control, at the right tempo... You can just see the day when he's going to do that more consistently, because he's literally already got the moves at in-game speed and against live defenders. Things to look forward to, ironically enough, as he slows down physically. Or he had this beautiful sequence against the Raptors (ugh, hometown, ugh) that was just quick, crisp, snappy stuff. Bargs is too slow to fall for most fakes anyway, but he's actually good about staying down with his arms up in the post and Blake was going "eh, eh? Take it. No? Try this. No? This." All one after the other without any wasted motion. He went three moves deep. Face up into back-down. Beautiful fast shoulder fake baseline, moved back middle, didn't have it, up-faked and then spun right to the hook. Missed, but the sequence was really, really nice and majorly encouraging.
Anyway, I could go on and on about him, but if you look at him against the Lakers, you can see a few things, and then I'll quit raving about Blake and go find a drool-bucket.
Elbow post against Gasol, nice jab step to pull-back jumper. Missed, but it was a good move and he didn't force the drive, which in this case was wise because he was like 18, 20 feet from the rim out on the wing and the entire LA defense was packed behind Pau. Next possession for him, good mid-post position and he went to the lefty hook again. Put a hesitation hitch in it and flicked it instead of going smoothly, but it's nice to see him going to the off-hand instead of forcing strong hand. Next one, catch-pivot that left him basically 13, 14 feet out left with his right foot roughly even with the top of the restricted zone, made a quick jab step baseline, then drove hard to the paint for the layup and the foul. Pretty, fluid, perfect move for the situation. Exploited a mismatch against Artest/Metta for a baseline drop-step to a made righty hook. Pulled an annoying face-up jumper against Pau. Flashing a lot of different things, right? He's showing a lot this year. Lots of room to improve, but so much is already right there that you have to love watching the guy.