Players move in and out of form, and there is not a lot that can be done about this, apart from exchanging players in bad form for those in good form. You can also make sure that players with bad form get to play in friendlies, as this increases their chance of improving their form. Every player has an attribute that shows his "current form" (the real figure at the moment) and another one that is hidden, called "background form", which shows where his form is heading. The current form is the figure applied for matches, while the background form is used by the program to compute where the player's form is heading.
Each week, during training, the current form figure (simply called form) of every player will change, moving towards the hidden background form figure. The exceptions are those players where the current form is already at the exact same figure as their background form. Current form is not changed at once to the figure of background form. Instead it moves in steps over several weeks, though the further away from background form they are the larger the steps will be.
After current form has been changed during training, there is a chance that background form is changed for each player. Every player has the same individual chance of having his background form change, and there is nothing you can do to influence this chance. In fact the only factor that decides whether or not the background form of a player is changed is a random chance. This means that the background form might change several weeks in a row for some players, but for other players it might not change at all for weeks.
However, when chance decrees that a player's background form will change, there are several factors that influence what the new background form will be. The most important one is whether or not the player has played a match during the week. If he has not his new background form will probably be lower than for those that did play. This is partly because it should not pay to have an enormous squad - if you do so, you will soon have a large number of discontented players not receiving match time and being constantly out of form. Besides, having many bench-warmers on the payroll is a bad investment. When the new background form is computed the following is taken into consideration:
- How hard you train (intensity of training)
- How good your coach's skill
- How many assistant coaches or goalkeeping coaches you use
- If a player has participated in a match during the week.
Note that in Hattrick form doesn't mean form in a physical context. It's not about a player having trained well or not. This affects stamina. Rather, form reflects a combination of all other aspects making it possible for, or preventing a player, from reaching his full potential. A player may be off form due to a loss of self-confidence or not having scored any goals lately. Maybe he's got some private problems. You could also imagine debilitating physical factors such as colds or similar, not simulated by injuries. In the same way, players in good form at the moment are on a roll.
An "excellent" player in "wretched" form is usually worse off than a "passable" player in "solid" form.
The intensity of training affects form. Players in a squad with a high level of intensity at training are generally in better form than players from a squad with a lower level of training intensity. Players' form is also affected by what kind of special training you choose.
Does this seem complicated? Remember, it's just as complicated for your opponent! You don't really need to compose the perfect team to win a game. The main issue is to assign players to positions they seem most suited for, and keep an eye on their form. Substitute players in bad form with players "on a roll". Give reserves in great form a chance to prove themselves. A simple system goes a long way.