Metrics

Math.  Literally things to factor in that, at least in my opinion determine a person's success or failure out on the field.  Depending on a weapon and their job, there's a lot of different things that one could value.  This post is ALSO in response to a serious foam fighters post.  All of these equations are TOTALLY made up and have no basis in anything.  Just spitballing.

Dueling Ratio

( (1ST / SL) + 1/2(F / FF) - (2(SL / ST) + 1/2(F/ FF))
ST shots thrown
SL shots landed
F Feints that were successful
FF feints that failed

Basically your hit ratio is what matters the most based on how successful you are at getting your shots to connect but by successfully getting your opponent to bite on fakes you either create openings for yourself or on a bigger field, another person so those matter too.  Your overall success or failure should be something you can compare to their relative success or failure.

Individual Contribution to a Field Battle

(2K + 1L) - (2D + 1L)
K 2 points per kill,
L 1 point per limb
minus
D 2 points if you died
L 1 point per limb taken (stabbed or slashed) otherwise.

Theoretically this means that taking one opponents sword arm and another opponents leg is about as valuable as finishing off someone who is already injured.  If you do nothing and die you have a negative contribution, if you kill someone an die you have a null contribution and if you kill at least one person and don't die you have a positive contribution.

Field Battle Team Analysis

(1FK, 1AK, 3Br, 2 Fla) / (1F, 1AK, 3B, 2Fla)

FK 1 point for killing an enemy flanker as this either helps you win the flank you're on, or is the act of counterflanking
AK 1 point for taking out an enemy archer while there's still a line
Br 3 points for breaching the enemy line by breaking through a hole in the line
Fla 2 points for successfully maneuvering yourself or your group into a good flanking position that causes the enemy line to crumble
over
F 1 point every time a flanker makes it past your line
B 3 points every time your line gets breached
Fla 2 points every time your force gets flanked

So basically your metrics for success as a group depends on how well you were able to win the flanks and maneuver, while taking out key objectives over the enemies ability to do the same.

Weapon specific

Redsman

2 K + 2 S + 1 L
2 points per kill, 2 points per broken shield, 1 point per legged opponent

-> Since there are already metrics for comparing an individuals skill this is more a useful thing when trying to decide between reds, who is more effective at being a support weapon based on the things they can do that would matter.  Breaking a shield on a line is as good as getting a kill because a person deprived of all of their protection has no hope of defending themselves from multiple opponents.

Spear

2K + 1L
2 points per kill, 1 point per leg

-> Pretty much same as above, except that spears can't break shields.

Archer

5L + 2P + 1K
5points for leadership, 2 points per polearm, 1 point for everyone else.  Nothing for limbs.