Blood Bowl Basics: Fouling

Everybody loves a good foul. Having a half dozen goblins hold a guy down while another jumps up and down on his head is both hilarious and an objectively great idea.

Great question, Aaröngandr! It turns out that the answer to that question is the same as the answer to all questions: LET'S LOOK AT THE MATH!

How A Foul Actually Works
Once per turn, you can foul an opposing player, making an armor roll against him. Like all armor rolls, you roll 2d6 and if the result is higher than the player's armor then he has to make an injury roll. There's one way that the foul roll is different than other injury rolls, though: your teammates can provide assists! Foul assists work just like blocking assists, which is to say that each of your teammates projecting a tackle zone onto the fouled enemy and not in any other enemy's tackle zones will provide a +1 bonus to the foul roll.
Since the lowest you can roll on 2d6 is a 2, a guaranteed armor break on a foul requires (enemy AV - 1) assists.
Now that's neat, but it takes a lot of dudes to guarantee an armor break on even the relatively crummy AV of 7. You can't always spare that many players, since a player assisting a foul is a player who's not really contributing to the rest of the game. So how many assists does it take to make an armor break likely?

It turns out: not very many! (Some rounding ahead.)

Enemy AV - # of assists	Armor Break %
1	100
2	97
3	92
4	83
5	72
6	58
7	42
8	28
9	17
10	8

An armor break is more likely than not at 6, which is just one or two assists respectively on the common AVs 7 and 8. So you can probably get an armor break... but then what's the chance of killing the guy you're fouling?

How An Injury Roll Actually Works
If you break a player's armor, that player has to make an injury roll on 2d6. Here's the short version of the injury table:

2d6 Roll	% of Occurance	Result
2-7	58	Stunned
8-9	25	KO
10-12	17	Casualty

There are a few common skills which alter the injury roll: Thick Skull moves the 8 result into the Stunned category (making Stunned 72% likely and reducing KO to 11%), while Stunty adds 1 to the injury roll to produce this table:

2d6 Roll	% of Occurance	Result
2-6	42	Stunned
7-8	30	KO
9-12	28	Casualty

What About The Ref?
The ref will get up the courage to eject your player from the game if you roll doubles on the armor break roll and/or the injury roll. If you don't break armor, you have a 1/6 (~17%) chance to be ejected. If you do break armor and as such cause an injury roll, you have a 11/36 (~30%) chance to be ejected.

Tying It All Together
Rolling the (non-stunty) injury results and ejection chances into our armor break table from before gives us this (including some smallish propagating rounding errors):

Enemy AV - # of assists	KO %	Cas %	Ejection %
1	25	17	30
2	24	16	30
3	23	15	29
4	21	14	28
5	18	12	26
6	15	10	25
7	11	7	22
8	7	5	21
9	4	3	19
10	2	1	18

TL;DR
You're more likely to remove the opposing player from the field than to get ejected if (enemy AV - # of assists) < 6. That's not really the whole of the consideration, though. You also have to be concerned about the fact that getting ejected causes a turnover (so do important moves before fouling!), the value difference between the fouling player and the fouled player (because it's generally worthwhile to trade a halfling for a wardancer or a gutter runner, for example), and any bribes you may have (each of which has an ~83% to cancel an ejection). Smart fouling will increase your game win percentage as well as your opponent rage percentage, so figure out the math and stomp some faces!

Blood Bowl Basics: Caging

You can't win a game of Blood Bowl without scoring points, and you can't score points without carrying the ball. So once you have the ball, how do you keep it?

One common tactic for holding on to the ball through an opponent's turn is called caging. As in the picture above, the ball carrier is surrounded by four teammates at his corners. In order to get to a space adjacent to the ball carrier, an enemy would have to dodge into three tackle zones. The roll needed to dodge into three tackle zones is (7-AG) + 2, meaning an AG 3 player needs a 6 (AG 4s only need a 5). Then, if they manage that, a block thrown against the ball carrier will be suffering two defensive assists from the adjacent cornermen:

A cage has a lot of strengths if it's constructed properly. But what are its weaknesses?

For one thing, a cage is easy to break if any of the cornermen are adjacent to an enemy.

The enemy adjacent to the cornerman knocks down (or at least pushes) the corner of the cage, opening up a route for a blitz on the ball carrier. Don't build your cage adjacent to enemies so this doesn't happen to you! If the enemy wants to knock a corner off your cage, make them spend their blitz doing it so they can't blitz your ball carrier afterward.

Cages aren't unstoppable, though. Here are a few strategies for dealing with an opposing cage:

Blitzing the Corner

The easiest and weakest strategy. You can blitz a corner off the cage and then run in one or two more defenders to stand adjacent to the ball carrier. This is far from a sure defense as your defenders end up adjacent to opposing players who may just crush them with blocks to free up the ball carrier. It's also easy for the ball carrier to escape with a single dodge after the offense rearranges a little:

While a corner blitz will rarely stop the offense from advancing the ball by itself, it can be effective if combined with a solid defensive formation that prevents the cage players from opening up space for the ball carrier to run. It can also be effective if part of the cage is made of weaker players, as you can position your encroaching defenders next to them to reduce the likelihood that the offense will be able to knock you off of the ball carrier.

Stalling

A classic column defense won't break the cage, but it will make advancement difficult. The offense can only blitz one of the defenders, meaning that there's no way to open a tackle-zone-free hole. They'll have to spend an entire turn getting men adjacent to the column defenders in order to beat them down on the next turn. Stalling defenses are most effective against slow teams; agile teams may be able to throw a pass over the stalling defense or just run around it. This defense also sometimes fails against stunty teams, who may be able to just roll right through the remaining tackle zones after blitzing one defender down.

Punish the Others

A cage eats up almost half of the offense's players, and ideal cornermen are tough players who are difficult to knock down. This means that the offense is short-handed elsewhere on the field, and the people being left out alone are likely to be playmakers like catchers. If you can spare a couple of players to set up a loose defense in front of the cage in order to slow the ball carrier down, you can often gang up on these other important offensive players and attempt to take them out of the game. Beat them down and maybe throw some fouls if you have a cheap player you're not afraid to lose (or a bribe). This will sometimes allow the offense to score, but it's often okay to let an early point slip through if it lets you secure a man advantage. This defense is most effective against teams with important offensive players who have low AV, such as elf catchers.

Special Support

Finally, some teams have special tools that are particularly well suited to breaking cages:

• Players with Leap such as Wood Elf Wardancers can safely leap into the space adjacent to the ball carrier, allowing them (with supporting players denying defensive assists) to get easy blocks on ball carriers.
• Very high AG or stunty players can sometimes just dodge straight into the cage for a similar shot. 
• Goblin Bombardiers or hired wizards can drop an explosion right on the ball carrier, potentially wiping out the whole cage (and even if the explosion doesn't get the ball carrier, it may wipe out enough corners to allow for an easy blitz).
• Throw Teammate (available to Goblin, Underworld, and Halfling teams) can sometimes be effective. A thrown player can land safely in a space adjacent to the ball carrier or he can even be used as a missile to knock down the carrier or one of the corners to allow for a blitz.
• The Vampire team's Hypnotic Gaze ability can shut off the tackle zones of one or more cornermen, which also allows for an easy blitz (and most ball carriers aren't going to stand up to a Vampire blitz very well).