My post on strategy versus player evaluation generated a lot of responses. Rob noted that when it comes to keeper leagues, it's also a good idea to know which types of players are valued more than others:
I finally, this season, figured out that strategy was important... My league goes crazy for closers in-season. So I loaded up at the draft and traded them away all year to get myself ready for 2013 and beyond... I'm middle of the pack now, but have a great chance to be a favorite heading into next year. (Pat myself on the back - I have Mike Trout, Matt Moore and Jason Heyward for less than 8 bucks each thanks to this strategy)
Absolutely (and great job Rob identifying a soft spot in your league and taking advantage). Part of any winning strategy is finding a trading weakness in your league or at least among a couple of the owners in your league and take advantage of it. I've had success over the years with tactics including but not limited to:
Playing the Saves Game
In addition to Rob's suggestion, this can work the other way as well. Some owners give up on saves too easily and are willing to trade a closer for 50 cents on the dollar in early to mid-May. Since there are only 14 closers in A.L.-only and 16 in N.L.-only, I might be aggressive early and try to get a couple so I can try and seal the deal in the category.
I always like to have a few farm players in tow because I know that some owners go crazy for rookies. These guys typically don't come up until a year or two after I deal them, so statistically there is zero chance my former players will help an opponent. I'm also not giving away stats in a deal where I trade Miguel Sano. You don't want to mortgage your future for a marginal return, but if you can get enough value back to win, make the deal now and worry about next year next year.
Some people call it category dumping, but I've taken to calling it category optimization. My home league is 25 years old yet most teams still aren't willing to recognize when they're dead in the water in a category and cut their losses to try and bulk up elsewhere. I'm willing to throw a category overboard if it improves my chances at winning.
These are merely a few ideas. The important thing - as Rob points out - is to find your league's weakness and not give up until you've exploited it.