There is nothing quite like the rush of pulling the Z, especially if you already have the Q, U, and I. You feel a certain benefit from the fickle draw of tiles that will help you win the game. And if you play smart, you probably should. I've not kept any statistics, but I suspect that drawing the four high point tiles increases your odds of winning game substantially, as long as it is not on your last draw! The high point tiles are extremely valuable in each word game. Their point totals also vary by each of the three big games (I've also included the K):
|Tile||Scrabble||Lexulous||Words with Friends|
|J to Average||4.3x||3.5x||4.7x|
|K to Average||2.7x||2.6x||2.4x|
|Q to Average||5.3x||5.2x||4.7x|
|X to Average||4.3x||3.5x||3.8x|
|Z to Average||5.3x||5.2x||4.7x|
One can also see that their relative value varies with each game as well. scrabble show a large bias to the Z and Q that is maintained in Lexulous. The X has the same point value in all three games, but on a relative basis is the most valuable in Scrabble and least valuable in Lexulous. It is also one of the most flexible tiles to play with common 2-letter words including AX, OX, EX, XI, and XU. All the vowels work!
Ideally you place the high point tile on a Triple Letter Score in combination with a Triple Word Score (possible in Words with Friends) and sound the death knell for your opponent. This results in a 9x multiplier on that tile. Doubling the X up on a Triple Letter Score with two simple words will get you a 6x multiplier. However, sometimes you are just trying to clear your rack of that pesky Q since you don't have a U or all the Us have been played. You spy an open I and collect your 11 points. Your opponent then plays QATS off on a Double Word Score using your Q for 26 points. Instead of taking a lead with the Q, you just fell behind by 15 points. When playing off a high point tile, it is important to see how your opponent might be able to use that tile as well. How many times can they score those points? If you score it 9x and they wind up scoring it 3x, you are still ahead by 6x of the tiles worth. However, if you get 2x and they get 3x you've fallen behind and that is a bad play.
Getting caught at the end of a game with a high point tile that you cannot play has two ramifications. The first is a points consideration. If your opponent can play off their tiles they then add the value of your tiles to their score and you lose that value. For the Q in Words with Friends, this is a 20 point swing and can make or break games. The second problem is a little more subtle. If your opponent knows that you have a Q at the end and they know you cannot play it, they can take a more relaxed approach to scoring points and look to maximize their point total, by playing just one or two tiles at time. This is a another benefit and can contribute another 15-25 points to a score. I've successfully used this strategy to beat opponents.