The King of Fighters 2002 UM/Defense
There are attacks that you can and can't block. Those you can't block are Throws and unblockables. Like most traditional fighters, attacks that you can block are sorted in 3 categories depending on how the player can block them. They are low, mid, and high/overhead.
Lows have to be blocked crouching, by holding downback. The universal lows are cr.B and cr.D with varying speed, range and other properties among the cast. A good cr.B with a good conversion goes a very long way in KoF as it's usually a preferred stagger, meaty, roll punish, low profile, and trap after an empty jump. The sheer versatility of cr.B's is one reason you'd usually default to block crouching but remember that the opponent is aware of that so they could hit you with an overhead instead if you don't keep your eyes open. Note that some characters also have a standing normal that hits low, usually cl.B like Kyo's with some of the few exceptions being K' and Seth's cl.Ds.
Other fairly common lows are low command normals, their motions may vary but they are usually slides done with df+B or df+D. As opposed to standing overhead command normals that lose their overhead property when canceled into, every low command normal still hit low when canceled into except Joe, Ramon, and Ex Robert's df+Bs. This means that a blockstring could start with a normal that you can block standing then a command normal you have to block crouching, yet another reason why defaulting to a crouch block when possible is standard.
The last and rarer examples of lows are some specials/supers like Mary's b~f+B and even rarer are some specials that become low after traveling a certain distance, like Mary's b~f+D and Leona's qcb+K.
Mids can be blocked crouching, by holding downback, or standing, by holding back. These make the vast majority of moves and specials on top of standing overhead command normals that become mid when they are canceled into. Unlike other jumping normals, remember that j.CDs are mid as well.
While they can always be blocked crouching or standing, there's a chance you'd slightly walk back before blocking if you're standing as opposed to crouching. The difference here is that slight back walk will tend to give the opponent better frame advantage or in rarer cases make whiff a move you were expecting to block first, which may mess up your timing to then punish it. In rarer cases, crouching may also make part of a move miss on block or on hit, essentially giving you more time to punish it and reducing the overall pushback you'd take if you were standing. Yet another set of reasons why you should default to block crouching before adapting to the opponent's mix-ups.
The only downside of crouch blocking when a mid is coming are the very few moves that travel in a parabola and would give the opponent better frame advantage if you block them crouching. The two most relevant moves of the kind are Kyo's rdp+K and O.Chris' qcb+P.
High / Overhead
Highs/Overheads have to be blocked standing, by holding back. The universal highs are j.A/B/C/D, j.CD is a mid, and other common ones are standing overhead command normals, standing overheads for short, and a majority of air command normals. The only grounded normals in the game that are overhead are Nameless' and Foxy's cl.Ds.
It's important to note that standing overheads lose their overhead property to become mid when canceled into on hit or block, not on whiff. So aside from Bao's f+B, Hinako's f+B > B and Lin's df+C that will remain overhead regardless of the cancel, once you block the opponent's normal defaulting to a crouch block isn't a bad choice. The opponent can still trick you by delaying the cancel, effectively keeping the standing overhead in its raw state with its overhead property.
Between that and instant overheads, it's because of how good of a default option a crouch block is that "when will the overhead come ?" is a question you will be asking yourself very often in neutral knowing that blocking most standing overhead will at best grant you a punish and at worst end your opponent's turn at offense.
Guard Cancel (GC)
Guard Cancel CD, GCCD (aka GC Blowback, Guard Attack etc.)
Press C + D while in blockstun. It cancels the blockstun by a blow that knocks down the opponent. The Guard Cancel CD has short frames of invincibility at startup, but has a recovery. It can get you out of a lot of attack strings while you block, and resume the pace of the match. It does little damage when it hits (it is possible to kill an opponent if it removes the remaining life to them). However, its use is limited by 3 factors:
- It will cost you one level of your super meter
- Your opponent might try to bait your Guard Cancel CD by making you whiff a standing CD while you're in blockstun, which has a slow startup and exposes you to heavy punishment. If you sense that bait attempt, just try to block instead.
- This move is not instantaneous and it does have startup. You cannot punish EVERY attack with a Guard Cancel CD successfully, and you can be exposed to punishment at the end of it.
Guard Cancel AB, GCRoll (Break Roll/Guard Roll/Guard Cancel Roll)
By pressing only A + B or back + A + B back (to Guard Cancel Roll backwards), while in blockstun, it is possible to roll forward or backward. This roll is completely invincible and unthrowable, and has no frame of recovery. This is one of the most important defensive elements to learn and master, but also one of most outstanding features of the defensive system in KOF.
- It will cost you one level of your super meter
- If performed at the wrong time and inaccurately, a punishable and fully throw vulnerable regular, normal roll may happen instead or a crouching A (See also Details of the system: priority buttons).
Quick Recovery (Recovery Roll/Fall-breaker/Tech-Roll/Quick Rise)
When hit by a move that'd lead to a soft knockdown, if you press A + B just before touching the ground, you will perform a 'recovery roll' or 'quick recovery'. It's a sped-up animation of a normal roll that's fully invincible and unthrowable from start to finish. For the pros of recovering faster, giving your opponent less oki or even punishing them for using a move with too much recovery, and denying any OTG, you lose the brief wake-up throw invincibility from waking up off a knockdown.
You'd usually recovery roll every time you can but against characters with a strong command grab or proximity unblockable, staying on the ground to remove that move from the things you have to consider as you wake up is a viable option. An option that you don't have against Ex Robert's d~u+P proximity unblockable as it's bugged.
Recovery Roll Speed
Characters have different recovery roll speeds. The differences are listed here:
- (-F) Faster recovery roll
- (-7F) - Xiangfei, Krizalid
- (-5F) - Maxima, Kasumi, Angel
- (-3F) - Mai, Chris, Chang
- (-2F) - Whip
- (-1F) - Shermie, Leona
- (0F) - Kyo, Shingo, King, Kusanagi, Kyo-1, Kyo-2, Nameless, K', Athena, Yuri, Goenitz, Zero, Igniz, Geese
- (+1F) - Chin, Iori, Mature, Vice, Ralf, Clark, Ramon, Clone Zero
- (+2F) - Billy, Kula, Joe, King, Foxy, Omega Rugal
- (+3F) - Daimon, Takuma, Ryo
- (+4F) - Robert, Benimaru, Yashiro, Yamazaki, Vanessa
- (+5F) - Kim, Kensou, Terry, Hinako, Heidern, Jhun
- (+6F) - Bao, Andy, Seth
- (+7F) - Choi
- (+8F) - Lin, Mary
- (+9F) - May Lee
- (+F) Slower recovery roll