Blocking, knockdowns and posterizers

A block goes through three checks in order: timing, then reach, then a roll on your Block stat. The first check you fail decides the message you see. Strength plays no part in any of them. It only matters afterwards, for the body contact on dunks: who gets knocked to the floor, and where a blocked ball flies.

What the failure messages mean

Every message except "Insufficient Block Ability" only appears when you were within 4 units of the shooter. Farther away, a failed block shows nothing.

"Too early" covers four different mistakes, so it's the message to think hardest about. Jumping at a pump fake, rising before the ball goes up, and overshooting the ball all show it.

Timing

The shooter's animation marks when it can be blocked. Your jump counts if you start it after that mark opens, and early enough that your hand peaks before the ball is gone. The cut-off is the end mark, or the moment the ball would score minus your own animation's time to reach the ball minus a small margin, whichever comes first. A slow block animation therefore has to start earlier.

Reach: Block Range and Block Height

At the moment your block animation swipes, the game places your hand and the ball and measures the distance. If the ball is inside a sphere around your hand, you reached it:

• Block Range is the sphere's size. Effects such as "Blocking Range +0.2" make it bigger.
• Block Height is how high your hand is. It decides "too low" against "too high".

When the ball is outside the sphere, the game checks sideways first:

• Too far sideways: Insufficient Block Range. On a jump shot where you overshot, so the ball sits between your body and your hand, you get too early instead.
• Within sideways reach but above your hand: Insufficient Block Height.
• Within sideways reach but below your hand: too early.

The Block roll ("Insufficient Block Ability")

Once timing and reach are both good, the game rolls 0–9,999 against a block chance. That chance compares your Block stat with the attacker's Block stat, not with their dunk or layup stat:

• Jump shots can't fail this roll. Close shots, mid-range and threes get a +100% bonus, so if you're on time and in reach, the block happens.
• Layups get +10%, dunks nothing. "Insufficient Block Ability" is a dunk and layup message.
• You only lose the roll when you're more than 40 Block behind. Base Block runs from about 55 (Kuroko) to 110 (Murasakibara, Jason Silver), so this mostly happens when a guard meets a big man at the rim.

Strength on a successful block: knocking the dunker down

Strength here and in the next section is each player's full Strength, upgrades included. Base Strength runs from 54 (Kuroko) to about 105 (Murasakibara, Jason Silver, Iwamura).

When you block a dunk, the game rolls once more to choose a hard knockdown, a light knockdown or a normal blocked reaction. Without bonuses, the hard and light chances are equal:

Each chance is capped at 50%. Block Knock Down effects (for example "Block Knockdown Rate +", or Jason Silver's skills) add flat points to the hard chance. Blocked layups and jump shots always get the normal reaction.

Strength on a failed block: posterizers

When a dunker collides with a defender who jumped to block and didn't win the block, and the defender is in front of them, the game rolls to see whether the defender is posterized: knocked to the floor (hard) or knocked away (light). Each defender is rolled once per dunk.

The dunker gets a 5-point head start: at equal Strength they still posterize about 9% of the time.

Posterizer Chance is the dunker's flat bonus on top of these numbers, added to the hard chance, the light chance or both, depending on the effect. Character skills add 1–5% (some much more), and the Pressure, Momentum and Core traits each give +0.7% (Traits). Those three traits sit in defense slots, but the bonus only counts when that player is the one dunking. At typical Strength gaps, +10% Posterizer Chance is worth as much as 30–40 extra Strength.

The defender's "Reduce the chance of being knocked away when blocking" effects subtract from the hard chance only (Liu Wei and Kiyoshi each have −10%). Both chances are capped at 50%.

Strength and where a blocked ball goes

On every successful block, the game takes your Strength minus the shooter's, adds your Block Strength Difference bonus, and uses the result to weight which path the blocked ball follows. The bands are 0–20 (anything below 0 counts as 0), 21–100, 101–150 and 151+. Strength gaps alone stay well under 100, so the top two bands come from Block Strength Difference effects on skills. Which band sends the ball where hasn't been worked out yet.

On defense

• Wait for the ball to go up. A pump fake, an early jump and an overshoot all show "too early". Most failed blocks are timing.
• Get to where the ball will be, not just near the shooter. Block Range and Block Height decide reach. The Block stat only comes into play once you've reached the ball, and only on dunks and layups.
• Leave dunks on big men to your big men. A guard more than 40 Block behind can lose the roll even with perfect timing, and a missed block next to a stronger dunker is a posterize chance.
• Block jump shots freely. On time and in reach, they always succeed, and there is no knockdown roll.
• Strength wins the aftermath, not the block. A center 30+ Strength above the dunker knocks them down on almost every dunk block.

On offense

• Dunk on weaker blockers. Strength and Posterizer Chance both help, and a defender who loses the block can end up on the floor.
• Use your Block stat even as an attacker. Your own Block stat lowers the defender's chance to win the roll on your dunks and layups.
• Fake before you shoot. A defender who jumps at the fake gets "too early": the game treats a jump before the ball is released as a failed block.

The exact formulas, table rows and code addresses are in the blocking reference.