Blockers! is a simple game to learn, and yet there are many strategies to try.
You have two goals: to end up with as few groups as possible on the board, and to avoid capturing too many tiles of the same color. How you choose to balance these two goals determines your personal style of play.
For instance, you may choose to focus on having as few groups as possible at the end of the game. This leads to an Aggressive style of play, because you will need to relentlessly block and attack your opponents in order to accomplish your goal.
Try to control one or even two of the four corners of the central region on the board. Don't be afraid to capture, but always look for opportunities to capture the colors that you haven't attacked yet.
Alternatively, you may choose to focus on capturing as few pieces as possible. This leads to a Peaceful style of play, since you will mostly avoid direct confrontation with your opponents.
Avoid the heavily-contested areas around the central region of the board, and instead use the central squares of the four corner regions as your anchor points. You may even try the Edge Strategy, playing only along the outer edges of the board.
When playing a non-confrontational strategy, you will probably end the game with three or more groups on the board, but if you've captured very few pieces, you'll be a solid contender.
Between these two extremes lies the Balanced strategy. If you have more groups on the board than captures of the color you've captured the most, focus on connecting your existing groups and avoiding starting new ones, and be willing to capture in order to do so.
If, on the other hand, you have too many captures of one color, avoid capturing that color at all costs, even if you must create more groups to do so. Your goal is to end the game with a roughly equal number of groups on the board and captures of the color you've captured the most.
You'll have more groups than the Aggressive players have, and more captures than the Peaceful players have, but your combined total may still be lower than anyone else's, giving you the win.
No matter which strategy you prefer, the tactical possibilities are endless!