This guide is intended not as competition to the other guides but as a supplement to throw hard numbers at the issue. The below numbers represent the percent chance you have of pulling any one particular card (in this case an in-form card) from each coin spent. This is an important distinction from a "per-pack opened" odds as packs cost variable amounts of coin. Also, the odds change each week depending on the number of each quality available in the TOTW. To determine which pack will provide the highest odds of pulling an IF card for your coins spent multiple the below numbers by the number of equivalent quality players available in the TOTW (including subs and reserves).
Bronze: 0.0000762% chance/coin spent
Silver: 0.0000158% chance/coin spent
Gold: 0.0000286% chance/coin spent
In case no one has mentioned it I recommend following http://www.ultimateteam.co.uk/
on twitter and setting a mobile alert for when they tweet. They announce all happy hours, which are the best way to get an IF player.
105 pages. x50 each page.
5250 total players
.019047% ~ chance of pulling any one particular player
.057141% ~ chance assuming three opportunities per pack
.00057141 chance/750 coins spent
.00000076188 chance/coin spent
.0000762% chance/coin spent
101 pages x 50 each page.
5050 total players
.019802% ~ chance of pulling any one particular player
.059406% ~ chance assuming three opportunities per pack
.00059406 chance/3750 coins spent
.000000158416 chance/coin spent
.0000158% chance/coin spent
28 pages x 50 each page.
1400 total players
.071429% ~ chance of pulling any one particular player
.214287% ~ chance assuming three opportunities per pack
.00214287 chance/7500 coins spent
.000000285716 chance/coin spent
.0000286% chance/coin spent
3 opportunities (players) per pack opened
Contents of the packs cannot be predetermined nor controlled
Only rare packs are purchased.
Players in packs will only be of that packs quality.
TOTW players are all equally weighted.
FUT Head database. Tried to use UltimateDB, however you cannot view all of the players in a single quality. If someone can provide a data dump for all the FUT player cards this could be more accurate.
The only variable in this is the number of players of quality in the TOTW. I have opened at least 200 Silver packs, 100 Gold Packs, and 250-300 Bronze packs and have not found a single IF player to finish this achievement off. Lately I've been opening solely Silver packs, which you can often break even on if you auction everything off, however the results of these statistics clearly show that unless the majority of the TOTW is silver, these provide the worst odds. Gold will almost always provide the best odds, as that is what the greatest number of the TOTW players are and where the least competition is. Only two bronze players in the TOTW will actually outweigh the chance for any other quality, however you will need to open many, many packs, and making your money back will be a slow process. If you are a stats person and see a mistake in my math please help me out! Good luck.
HELP: For example this week (11/7/2012) has 11 Golds, 5 Silvers and 2 Bronze players. So the odds would be .0003146%, .000079% and .0001524% respectively with Gold have the greatest chance per coin spent.