Okay, playing on a speed feild most of the time during my paintbal career, I can be of a little help. I'll make it in list form so it's easier to read.
-Play tight. Always keep tucked in close to the bunker as much as possible. This of course will drasticaly reduce the risk of being hit on your sides.
-Look down the barrel, not it's side. This helps me know where the paint is going to fly. Try it out at the target range and see if it works for you.
-Spend time at the target range to learn the arc patter of the way your marker fires. For playing the back, this will be a big help.
-Back players should always be talking (or yelling). "We got one player moving up in the snake, near the back!" Back players should be as detailed as possible so the front players don't have to spend tme searching for the opponents.
-Front players communicate the the back players so they always know that you're in tact and still in the game. Front players should always be looking for a new useful bunker that proves to be an advantage over the current bunker they occupy. Gain ground on the opposing team and somtimes even sacrifice one person to take out two of thiers in a bunkering move; but that should only be done to end a game or if your team would outnumber them after the sacrifice.
-Yell for cover when you need it, and people who hear the call for cover, immediately put down fire at the other team. It isn't uncommon for people to concentrate on one and only one person, so you may catch an opposing team member wide open.
-Be unpredictable; never come out of one side of the bunker more than three times in a row, and never look over the top of the bunker. You my have a great view of the feild, but the other team has a great view of your head and hopper. Don't be obvious about future actions for example: "Hey ------, Bunker that guy!" Develop a code if you must, and remember it like the back of your hand.
-If a ref is in the way of a good shot at the opponent, take the shot. It is a rare case, but has happened to me. That same ref agrees that I should of taken the shot and he shouldn't of been there.
-Never argue with the referee. Speedball is a fast paced game and they don't have time to stop and argue. If you are 100% certain you weren't eliminated or whatever may be the case, ask them nicely why they made the call. That's thier job and they'll be more than happy to tell you.
-Whatever happens in the game, have fun. Even if you were severely beaten, remember what you did wrong and correct yourself the next game. Playing better teams than yours is the best way to learn.
-Show enthusiasm in what you do and be honest. Use sportsmanship in whatever the case may be (few exceptions), and you won't be disliked by anyone.
I hope I helped, and you can utilize the points I made to improve your teamwork and game.
