Electronic Arts has acknowledged problems with some of the rarest and most talented player cards in FIFA 16's popular Ultimate Team mode, following a weekend in which the community pried apart the mode and discovered inconsistencies that some say have been a part of the game for years.

FIFA's subreddit on Sunday posted the results of a user investigation into how Ultimate Team, a tremendously popular card-collection/player-management mode for the global best-seller, handles a concept it calls "chemistry." That is, when assembling a team, the user is told that players who are countrymen or teammates (or both) of another player adjacent to them in the formation will receive an attribute boost.

FIFA players had complained that special-edition cards — that is, the rarest and most valuable in the game's population — had long felt unduly sluggish and underpowered. One user posted this analysis in which common cards of top stars (called "day-one" cards) got the chemistry benefit and outperformed special-edition counterparts — meaning that the game does not apply "chemistry" to the Ultimate Team's most valuable players:

(In the above, "NIF" means "non in-form." This is the basic edition of the player, available on the day the game launches. "In-form" players appear over the year, with higher ratings linked to their real-world performance. "IMOTM" means "International Man of the Match" and is one of the rarest and highest-quality versions of the player.)

This morning EA Sports acknowledged "a potential fitness and chemistry inconsistency in some [FIFA Ultimate Team] items."

"After hearing this, our teams were in over the weekend and continue to thoroughly investigate the information," EA Sport said in a statement. "We will keep you informed with updates from the investigation. Our commitment to a fun, fair and secure experience in FIFA is ongoing, and as a community your feedback helps us achieve that goal."

"Fitness" is another feature of Ultimate Team, under which players used in consecutive games see decreasing performance until given a chance to "rest." Users have also noted that this limitation does not apply to special-edition performers, suggesting there is some glitch or mistake within Ultimate Team's logic, potentially related to the "chemistry" glitch.

However, other users allege EA Sports has opaquely nerfed FIFA Ultimate Team's best players for competitive reasons (Ultimate Team features player-vs-player live competition), and isn't being honest about their value.

Over the weekend one user posted this video in which an advanced dribbling move, which should have been available to a chemistry-boosted star, was in fact not. This seemed to prove that superstars didn't get the "chemistry" benefit.

This conflict may seem esoteric to others but it isn't to FIFA gamers; real money can be spent on the game's in-house currency to acquire packs of players. Higher-rated packs deliver better players, and cost larger sums. An auction window also facilitates the purchase of individual items, with the best ones commanding even larger prices.

FIFA, which originated the Ultimate Team concept in 2009 not only for EA Sports, but also competitors like MLB The Show and NBA 2K, drives a huge portion of the $692 million in Ultimate Team-related revenue that Electronic Arts reported to investors in its most recent fiscal year. (FIFA, Madden NFL, NHL, NBA Live, and UFC all have Ultimate Team modes.) That figure is up 26 percent from the previous fiscal year.

This conflict has left many in the FIFA gaming community feeling as if they'd spent huge amounts of currency, real or virtual, without getting the value they were promised. FIFA's subreddit demanded a boycott of all virtual currency purchases until some official acknowledgment was given by Electronic Arts.

Currently, users are probing other performance bonuses made by FIFA Ultimate Team — "momentum," for example — while waiting on a fuller accounting and resolution from EA Sports.