I disagree about buying a bunch of speed merchants. Unless you're a spammer and don't want to play real football.
My approach has been more to build my team all-around, i.e. realistically, so I don't have one 7 million dollar player and then a bunch of players worth next to nothing.
Here are my suggestions:
1. You have too many substitutes. If you get players with good stamina and form, then you can get by with maybe only 1-2 subs on the bench, if you're stategic about it and choose players who can fill a variety of roles as your subs. Also, I would even go as far as to say you only need one GK. How often is your GK ever going to be injured? If it happens, put someone out of position in net and take the loss, but it will probably never, ever, happen.
2. Get rid of as many default players as you can and replace them with player worth similar amounts of money but who you feel are better bargains or better suited to their roles. I don't personally think there is s single default player who can't be replaced with a better player for a reasonably similar price or slight increase.
3. The goal should be to get your best 11 on the field. Again, don't worry about the subs. If your players have good stamina and form you should be able to get through most games without even using any subs. 1-2 is a good idea, but with the right team you need less is my point.
4. In order to do all this you need to fill your squad with several of the cheapest players in the game (5-10 thousand dollars each) so that you have the min # of players (16). You will see pretty much everyone playing the game does this since it allows you to maximize your squad with as little waste in terms of dollars on the pitch as possible.
5. Get a decent striker as soon as possible. He may cost more, but this position is so crucial. I use Huntelaar (about 3 million) but it took me a little while to get him.
6. As I said previously, try to find players who are a bargain by looking for stats that are better suited to different positions. The players' base cost is based on their overall rating, so for example, Lyng is 59 overall, and costs what other 59 overall players cost (more or less), but if you play him as a SMF instead of CF his overall rating jumprs to 69 (a bargain). My CBs when I started were Cornostara and Simao, both DMFs and 10 better when played as CBs than in their normal DMF position.
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