When it comes to offensive play, the joker is an extremely important tile. Its most obvious function is as a guaranteed initial meld tile. Since by itself, the joker counts for the full value needed to make an initial meld. However, the odds of you being dealt a rack with at least one combination is pretty high, so you may want to consider holding back the joker to use later in the game as an offensive move.
It is usually a good idea to hold the joker for as long as possible. You do not want to lock it up for use with a specific group or run though. You should also keep the joker at the end of your rack and play the rest of the rack as if you didn’t even have it. This will keep you looking for the maximum number of combinations and sets. When it is necessary to meld, the joker will then be available to use to your best advantage.
There are going to be situations in which you may wish to have an opponent reuse your joker so that you can reuse it again later. To the beginner this might sound like an unusual gamble when you use the joker in hopes that they use it to add onto a meld that you may or may not have the tile to replace it with. However, the experts know that you have to take all possibilities into consideration. It is a way of taking advantage of all the odds in his favor, no matter how small.
Another example of when to use the joker offensively is when you are near the end of the hand. For example, say that you are down to three tiles, one of which is the joker, and none of them are playable on the table and do not form any combinations. This is actually pretty common and may happen to you quite often. You may think that you should dump the joker to get rid of the points but then you will still be left with two cards. Unless another player just happens to put down a meld in which you can use your two tiles you are in some trouble. Therefore, you should keep the joker and discard the highest and safest tile on your rack. That leaves you with 1 tile and 1 joker. Chances are you can use the joker and the last tile when another play melds their hand on the table. The odds are actually 28 to 1 that you will have something that you can use the joker and the last tile with. Unless you were extremely defensive player, then keeping the joker till the last possible moment in this situation is the best decision you could make.
The joker is the most dangerous single tile and it should be played with care. In spit of its high point value, it should be retained or played as a protected tile as often as possible. The only exception is when you are absolutely certain that an opponent is prepared to go out. You want to be in charge of the jokers as much as you can, and take advantage of every opportunity to reuse an opponent’s joker and place it in a protected position.