Please refer to the updated article at http://www.fantasyfootballuk.co.uk/viewtopic.php?t=12339

Hi, I have taken the liberty of presenting what we are doing here in an easy-to-understand article explaining how price changes work. Phrases in italics indicate that more research is required to confirm the statement. So, once they are proven, we can remove the italics.

Feel free to add in new rules as you deem fit as I don't profess to know everything about the topic and may have left out some points.

So I proudly present,

The FISO Law of Price Change

Definition:

Net Transfers In (NTI) = Transfers In - Transfers Out
Net Transfers Out (NTO) = Transfers Out - Transfers In

Assumptions:

1. Price changes occur between 02:15 - 02:31 BST everyday. This marks the start of a new day.
2. The price of a player will not change by more than 0.1 in a day.

Price Increase:

1. The NTI for a player need to exceed a certain threshold before his price will rise. The current figure we are looking at is 1.5% of the number of players at the start of the season.

2. If the NTI is smaller than or equal to the threshold at the time of the price change, the figure is brought forward to the new day.

3. If the NTI is greater than the threshold, his price will rise, then the NTI is reset to zero and recounted for the new day.

For example:

Player X
Assuming 770,000 players at the start of the season.
Threshold for price increase = 11,550 (1.5% of 770,000)

If the NTI = 15,000, his price will rise by 0.1 and his NTI will be reset to 0 for the new day. Therefore, he will need to get more than 11,550 transfers in for the new day before his price will rise again.

If the NTI = 10,000, his price will remain unchanged and will rise if he gets more than 1,550 transfers in for the new day.

Price Drop:

1. The NTO for a player need to exceed a certain threshold before his price will drop. The current figure we are looking at is 5% of the number of teams that have the player at the start of the new day.

2. If the NTO is smaller than or equal to the threshold at the time of the price change, the figure is brought forward to the new day.

3. If the NTO is greater than the threshold, his price will drop, then the NTO is reset to zero and recounted for the new day.

For example:

Player Y
Assuming 780,000 players at the start of the new day.
Teams selected by = 10% = 78,000 (10% of 780,000)
Threshold for price drop = 3,900 (5% of 78,000)

If the NTO = 5,000, his price will drop by 0.1 and his NTO will be reset to 0 for the new day. Therefore, he will need to get more than 3,900 transfers out for the new day before his price will drop again.

If the NTO = 3,000, his price will remain unchanged and will drop if he gets more than 900 transfers out for the new day.

Edit: Corrected the threshold definition.
Edit: Updated with new confirmations

Yes, this is exactly what we need. We need fellow forummers to record and post the above information as close to the 'Trigger Time' as possible, meaning 01:31-02:00, and 02:01-02:30 as we have narrowed the time to be 02:01 or 02:31 and the numbers are updated in half hours.

I will be taking note of players with Net Transfers In values very close to the threshold, but I cannot guarantee to be in front of the PC at that time, so I need the help of fellow forummers. But I will be glad to analyze the figures and help break the code soon!

good job malefice , keep it up

Ah, I knew there was a catch. Sorry, I need my beauty sleep.

Would this survice, it's easier for me to do as an image. taken at 11.59am for west ham.

I'd love to assist but:

a) I can't stay up until that time and get up for work at 7.30am at my age.
b) I'll probably be in a tent in Derbyshire over the Bank Hols - weather and laziness permitting.

whuuf, how do you get to those team pages on the Prem League site? I've never seen the data laid out as handily as that before.

That's absolutely perfect, whuff! You even included the time!

Can you give a 'site map' to where you found that page? Or post a link?

Thanks.

Flyman (still packing).

I'm afraid there is no direct link. I took screen grabs of the three pages then comped them together in photoshop. I might have enough time in the evenings to do another team as well. Let me know if there is a particular team you want me to grab.

Correct me if I am wrong whuuf... but you must be a fellow Apple Mac user to have such nicely renedered type in your browser

Last season price increases were caused by a fixed number of transfers in since the last price change for each player, as ferg successfully proved by predicting 10 out of ten price increases one day. This figure was 1% of the number of players in the game at the beginning if I recall correctly.

Unless they've drastically changed that system there may be some confusion to the figures being caused by the fact that Prem League only seemed to enable the price change system last night. Hopefully it'll be possible to get a clearer picture now the price change mechanism has been switched on. Assuming of course they don't switch it off again for an unknown period.

No. At the beginning of the season, FPL calculates a threshold. This threshold is 1% of the total number of players at season start. This season that's about 7700. That's the threshold that applies to ALL players when calculating price increases, regardless of how many people have him.

Thus, when a player gets +7700 net transfers in, his price goes up during the night.

I think squealy's right and there's a simple explanation.

The system wasn't turned on until Monday so any discrepancy between last year's formula - http://www.fantasyfootballuk.co.uk/view ... hp?t=11832 and this is explained by all the unnaccounted for transfers that occured over the weekend.

It's also quite sneaky as all the data I collected when the game started is now less accurate and the market may actually be based on the number of managers and teams (%) from readings taken on Monday not Saturday, which I guess no one has?

I wish I could help you there ferg but I can't, sorry.

It would be a pain in the bum if someone has to try and work it out exactly again like you did last season if I recall correctly.

I hope this is a simplified summary of all the above, is there anything wrong in the following as far as we know?

Player's price increases 0.1m if net transfers in since last price change > 11,500 (approx).
Player's price decreases 0.1m if net transfers out since last price change > 5% of teams selected by.
Changes activated daily at around 2am BST.


Great work everybody!

Out of interest reds363, where are you getting the 11,500 figure from?

Im not sure thats correct to be honest.

If it were Campbell, Mellberg and Zamora would have gone up on Saturday night as they all had over 11,500 by then.

It will be impossible to confirm the correct equation until after another night of price changes.

It may be that Ferg is correct and the system wasn't initiated until early Monday morning, if so the baseline we are all using is incorrect.

Also, the response from FPL.com on my query raises a question or two. When they say 'you know already', do they mean...

a) we know the equation already (they probably visit this site i would reckon)

or

b) we know that the formula has changed

????

Either way im a bit miffed, i was suposed to take a snapshot of the players i was tracking at 01.30 last night but came crawling in at 04.30 slightly worse for wear. The only figures i have are from 7.30am on 21st and 22nd, thats a big gap

I assumed they meant "you already know" that they won't reveal anything about the equation.

On re-reading i think you are right Squealy.

People have been saying 11,700 or 12,000 - we don't know exactly and probably never will but it's just a ballpark figure. All the players that went up had a NTI over 12k at the time, the closest player that didn't go up had about 11k?

I think it's pretty much a safe assumption that the program wasn't started till Monday - since I'm sure a handful of players were over 12,000 NTI by Sunday night and should have moved then?

Thanks for clearing that up. Think we'll have to collate the data for the next few days to confirm the suspicion that the price change mechanism is indeed started only on Sunday and not Saturday night.

I shall make the necessary changes in my post above.

That's the observation I made. Everyone of those who had price increases had more than 12k NTI. Closest to them are Kenny and Carvalho who had only around 10k NTI but their prices did not go up.



Think we can test for the 7700 (1.0%) and 11,550 (1.5%) threshold for the coming price change. Perhaps someone would like to make a prediction of which players' prices will change at 01:31 then check the predictions after the actual price change has occurred.

Edit: Corrected threshold value for 1.5%.

Sure am Jonathon, I'm fortunate enough to have both platforms to play with

As there is only four games tonight I don't mind grabing stats for all four teams before I head off to bed, probably between 1 & 2am. I won't be able to capture the increases till about 9.30 in the morning however.

A joy we will all have soon with Boot Camp and the like... if you can call using Windows a joy

btw: only two games tonight, did you mean 4 teams?

OK, going off the 1.5% for rises and 5% for falls these are my predictions...

Increases

Saha
Kenny
Carvalho

Borderline (shouldnt move, listed here for reference)

Kanu
Arteta
Armstrong

Decreases

Sommeil
Henry
Butt
Carragher (may not decrease as currently injured)
Giannokopolous
King
McCarthy
Rooney (currenlty suspended, not sure if this counts same as an injury)
Zokora

Borderline (shouldnt move, listed here for reference)

Bentley
Chimbonda
Djourou
MGP

I cant stay up any longer, have values recorded as of 23:30

There may be others not on my list.

If any night owls, or those in foreign parts could record the stats immediatley after the price change for the above players that would be great

I much prefer osx also but xp does have a few things going for it, especially in the way of gaming.

and yes sorry, four teams in the two games. I'm going to record at 1.25am

Good work reg. It'll be interesting to see the results of your experiment. Assuming you can do your maths of course.

As of 22/08 02:37 BST:

Player / Teams selected (%) / NTI

Campbell 12% +29079
Mellberg 7% +28979
Bridge 8% +23741
Terry 49% +16900

Bowyer 5% +18785
Parker 10% +14240
Campo 4% +14389
Lampard 26% +12605
Ronaldo 10% +12355

Saha 9% +31292
Zamora 13% +23159

As of 23/08 02:04 BST:

Player / NTI / Change from 22/08*

Kenny +14367 +14367
James + 10276 +10276
Mellberg +36785 +7806
Bridge +34266 +10525
Terry +21701 +4801
Carvalho +12989 +12989
Armstrong +8187 +8187

Bowyer +25079 +6294
Parker +17611 +3371
Campo +18112 +3723
Ronaldo +17518 +5163
Lampard +17262 +4657
Arteta +9961 +9961

Saha +46377 +15085
Zamora +30882 +7723
Shevchenko +6304 +6304
Kanu +10215 +10215

* Assuming the NTI is reset for players whose prices have risen at the start of the new day.

So I predict

1.5% (11,550) Threshold Price Rises:
Kenny
Carvalho
Saha

1.0% (7,700) Threshold Price Rises:
Kenny
James
Mellberg
Bridge
Carvalho
Armstrong
Arteta
Saha
Zamora
Kanu

We will soon find out!

Edit: Updated the figures when the prices did not change at 02:01.

There they go, sometime between 2:16 & 2:31

Kenny, Carvalho and Saha

Screenshot taken at 2:20 am:



Only Kenny, Carvalho and Saha have gone up - I think we have cracked that one!

Result!

The price change happened at 02:31. Kenny, Carvalho and Saha's price rose by 0.1. Therefore, 11,550 (1.5%) can be used as a rough figure for the price increase threshold.

As of 23/08 02:36 BST:

Player / NTI / Change from 22/08*

Kenny +14387 +14387
Carvalho +13000 +13000
Saha +46424 +15085

* Assuming the NTI is reset for players whose prices have risen at the start of the new day.