The model for AFL Fantasy pricing is a little more complicated than SC.
As each round is played, the model becomes slightly more complicated to look at, however the early Rounds, particularly Round 1, are simpl(ish) to look at.
A simplified version of the Rnd 1 price change model.
The new price = old price x W + score x (1 - W) x MN x R
W = weighting given to the old price, usually in Rnd 1 this is a little above 90%
R = the factor the MN has changed by
Let's use A Young and L Franklin in a simultaneous equation, to see what values we come up with for W and R. Keep in mind, the prices and price changes are heavily rounded (to the nearest 1,000) so this calculation is VERY approximate. You'd need to do a string of these equations to get a better approximate.
A Young: 420,000 = 387,000 x W + 112 x (1 - W) x 7042 x R
L Franklin 708,000 = 677,000 x W + 151 x (1 - W) x 7042 x R
Using A Young's equation to get a value for R, we get:
R = (420,000 - 387,000 x W)/((1 - W) x 788,704)
plug that into L Franklins equation, and you get:
708,000 = 677,000 x W + 151 x (1 - W) x 7042 x (420,000 - 387,000 x W)/((1 - W) x 788,704)
When we solve that, we find W = 0.9131 ie. 91.31% of a players Round 1 price carries through to Round 2, and only 8.69% of his price is open to adjustment. This becomes quite different as each progressive Round is played.
When we use that value to solve a value for R we get R = 1.092
Keep in mind, as I stated, these values are very approximate, because of the big rounding factor.
Based on these figures, only 8.7% of a players price is open for adjustment (so if a player scored a 0, he would drop by 8.7%.)
To maintain his value, a player needs to score at:
0.913 + (0.087 x 1.092) x last years average => 100.8% of last years average. (again, approx, rounding etc.)
Footywire have:
Witherden at a B/E of 147, I have him on a B/E of 88.0 x 1.008 = 89
Worpel at a B/E of 17, I have him on a B/E of 68.2 x 1.008 = 69
Because over 90% of a players price is retained after Round 1, it is the round with the lowest relative price adjustments, as each round progresses, that retained % for each round drops. Just as an example, after Round 2 it might be 86% of the original price is retained + 6% of the Round 1 adjusted price, and again, 8% is open to adjustment etc.
Quite happy to say I'm wrong, but let's see how it works out.