Player Rerates - Stats (original)
Players come with 13 skills, all of which are rerated each season based on their personal performance. In order to rerate a skill, the player must have played in at least 10 games in the past two seasons. These 10 games can be spread out among Pro, Farm or Junior leagues. By default, the Farm league's stats are worth only 25% and the Junior league's stats are worth only 10%. This is done so that players can be drafted, sent to the farm and then moved on to the Pro leagues and continue to develop / increase in skill.
Each stat is also weighted by the number of games they've played at each level. To do that we take the stat and multiply it by the number of games played at that particular level and then apply the percentage. We add up all the stats/weights and then divide by the total games played across ALL LEVELS to get the number we're going to rerate against. The reason we multiply by the number of GP at each level is to ensure each level's stats are treated equally.
We also add an Age Modifier against the stats from the last season. For players 30 and under, the modifier is 1.1. For players 31 and over, the modifier is 0.9. This modifier is multiplied against the stat for the last season only (not the previous season). The modifier is there to simulate the liklihood that younger players will get better each season.
We also add an Ice-Time Factor against the stats from the last season for ALL players. Last season's Ice-Time Average will have been modified by the Age Modifier and then is divided by the previous season's Ice-Time Average to give the Ice-Time Factor. This is done so that GMs are encouraged to give their players more ice-time to simulate on-ice development... basically you improve by getting more ice-time and experience.
We then compare the last season's stats to the previous season's stats and see what the ratio is. By default, if the ratio is lower than 0.8, the player will rerate down. Between 0.8 and 1.2 there will be no change. A ratio of higher than 1.2 will result in a rerate up. As with all things, however, life is uncertain. There is a 10% chance for each skill that the rerate won't actually happen... so a Rerate Down or Up will actually be No Change.
Formula and Sample Calculation
The formula basically works out to this:
prvStat = ((proStat * proGP) + (farmStat * farmGP * 0.25) + (junStat * junGP * 0.1)) / (proGP + farmGP + junGP)
lastStat1 = ((proStat * proGP) + (farmStat * farmGP * 0.25) + (junStat * junGP * 0.1)) / (proGP + farmGP + junGP)
lastStat2 = lastStat1 * AgeModifier // NOTE: If it's better to have lower stats (like PIM), we divide by AgeModifier instead of multiply.
lastStat = lastStat2 * IceTimeFactor // NOTE: same as above... we divide if the stat is better when lower.
RerateRatio = lastStat / prvStat // NOTE: if it's better to have a lower number, we do prvStat / lastStat instead.
EXAMPLE: Alexander Crosby - Scoring
We will use Alexander Crosby's stats from Season 26 and Season 27.
We first need to figure out the IceTimeFactor, since that gets applied to pretty much everything. To calculate IceTimeFactor we use the formula above and stop once we know lastStat2.
prvIce = ((0 * 0) + (0 * 0 * 0.25) + (1287 * 46 * 0.1)) / (0 + 0 + 46) = 128.7
lastIce1 = ((995 * 7) + (971 * 39 * 0.25) + (0 * 0 * 0.1)) / (7 + 39 + 0) = (6965 + 9467.25 + 0) / 46 = 357.22282
lastIce2 = 357.22282 * 1.1 = 392.9451 // NOTE: age modifier
IceTimeFactor = 392.9451 / 128.7 = 3.0531864
Now that we have the IceTimeFactor we can figure out the RerateRatio for Crosby's SH skill.
prvGoals = ((0 * 0) + (0 * 0 * 0.25) + (37 * 46 * 0.1)) / (0 + 0 + 46) = 3.7
lastGoals1 = ((1 * 7) + (14 * 39 * 0.25) + (0 * 0 * 0.1)) / (7 + 39 + 0) = (7 + 136.5 + 0) / 46 = 3.11
lastGoals2 = 3.11 * 1.1 = 3.43 // NOTE: age modifier
lastGoals = 3.43 * 3.0531864 = 10.472429 // NOTE: applying the IceTimeFactor to lastGoals2
Now we can figure out the Rerate Ratio:
RerateRatio = 10.472429 / 3.7 = 2.8303862
The ratio is above 1.2 so they'll have a 90% chance to rerate up in the SH skill.
Fighting and Chemistry
The Fighting skill uses the same formulas as above, except we do not add extra weight to Pro, Farm or Junior fights. In the case of fighting, the formula looks like this:
Fights = (proFights + farmFights + junFights) / (proGP + farmGP + junGP)
The Age Modifier IS applied to the rating, however, the IceTimeFactor is NOT.
The Chemistry skill is an optional skill that an owner or commissioner can choose to use for their league. The Chemistry skill rerates toward a perfect score of 5.5. If your player has an overall rerate of Not Applicable (meaning not enough GP in either season) or Decrease, the Chemistry will move 0.01 to 0.10 points towards 5.5. If your player has an overall rerate of No Change or Increase, the Chemistry will move 0.11 to 0.25 points towards 5.5.