How Injuries work

[chaos]

In the game, a player can get injured for the game, or injured for the period. But there are some players who can never get a game injury (except if they get hit by a goon, more on that later)!

What causes an injury?

When the game determines a player is getting knocked down (the check is successful), it will check if there should be an injury. The impact value of player will be used in the calculation. 

To determine if there will be an injury:

- Start with $A0 (160 decimal)
- RNG (result will be from 0 up to 160 decimal)
- Compare the impact of the player to the result (the impact value is calculated when the 2 players are about to collide, using their weight and velocity).
- If the RNG result is higher than the impact, there will be no injury. If it is lower or equal to the impact, there will an injury, as long as the clock is running (no injuries post whistle)

 

I should note that the impact value is cumulative. If the player was recently hit into, but survived the check (did not fall down), they will have a previous impact value stored. This value will decrease by 1 each frame (there are 60 frames in a second in Genesis). So if there are 2 checks in quick succession, the impact value will be much higher than from a single check. Also, any player collision causes impact, not just a check (bumping into a player for example, or getting hit by the puck).

 

Injury for the period or game?

Once the game determines there's an injury, it will now figure out the type of injury. In this case both the player who caused the injury and the player who is getting injured is used to figure this out.

Each player has an H/F attribute byte, which stands for Hand/Fight. Now fighting is not in NHL94, but the Fight byte is used to determine injury type. The Hand part of the byte is just the first bit, which would make the number even or odd. The Fight portion of the byte is always even. 

For example, Jeremy Roenick has an H/F byte of 3. The number is odd, which makes him a Righty. His fight portion of the byte is 2 (round the odd number down to an even number to get the Fight). 

Alexnder Mogilny has an H/F byte of 4. The number is even, making him a Lefty. His fight portion of the byte is 4 (no rounding needed).

 

Code to determine if injury for game or period:

- Get the Fight byte of the player checking, and divide it by 4 (no remainder)
- Check if the result is 0 (which would be an H/F of 3 or below)
	- If zero, the injury will be for the period

- If not zero (H/F of checker 4 or above):
	- Check if the result was 3 (H/F of 12, which is the max)
		- If it was 3, player is injured for the game
	- If less than 3 (H/F is 4-11):
		- Check the Fight byte of the player being injured
			- If the Fight byte is 2, 6, or 10 (H/F 2,3,6,7,10,11), the player will be injured for the game.
			- If the Fight byte is 0, 4, or 8  (H/F 0,1,4,5,8,9), the player will be injured for the period.

There are 5 "goons" in the game with an H/F of 12. When these players cause injuries, they will always be for the game:

Grant Ledyard (BUF)
Louie DeBrusk (EDM)
Shawn Cronin (PHI)
Tony Twist (QUE)
Basil McRae (STL)

In all other cases, player that have an H/F of 0,1,4,5,8 or 9 will never be injured for the game. 

So in the above example, JR will be injured for the game if he's injured by a player with an H/F of 4 or above. If Mogilny is injured, it will always be for the period, unless by one of the goons, then it's for the game.

Another fun example: If Mogilny injures JR, it will be for the game (Mogs H/F is a 4).

 

[IAmFleury'sHipCheck]

I've been waiting for this breakdown for decades. Thanks Johnny C!

 

[danTML7]

I'm kind of surprised there hasn't been some accidental or anecdotal reports of this throughout the years. Like, Ledyard is a Buf starter most commonly and I have played a lot with them, and I can't recall ever thinking "wow he always injures people for the game". 

Has anyone else retrospectively thought that they might have known some of this information by feel?

[segathon]

amazing!

[AdamCatalyst]

Oh wow! Interesting that "damage" is cumulative. Loving these breakdowns.