Safety play is essential with most pocket billiard games, especially 8-ball, which we'll concentrate on here. Most mid-level players have a basic understanding of safeties, but few achieve successful safety shots when an important game is on the line.
The key difference between a typical league-level safety shot and a professional safety shot is that the professional shot achieves two or more things. Simply hooking your opponent behind a ball is not sufficient is most competitive scenarios. We've all had instances in games where we hook an opponent, and they simply kick the cue ball off of a rail into their ball. These games usually result in the opponents kicking at their balls until one of them finally has a shot at something. Again, most average players at this point are only trying to avoid a foul, and any goals or plans on how to run the table and win the game are forgotten.
The key to safety play is not only hooking your opponent and making him try a difficult shot, but improving your own table as well. For instance, your opponent, playing solids, may have his three-ball blocking a pocket with four of your striped balls sitting around it in a traffic jam. One option for you is to attempt to cheat one of your balls around the three-ball, or carom your ball off of the three and into the pocket. Depending on how the three-ball sits, this might be the best option. But sometimes there is no way to get your balls into that pocket, and out of frustration a typical player will attempt to spread the balls to another part of the table, or try a very difficult cut shot into another pocket.
A safety option for this situation is what I call 'stealing your opponent's shot'. What you want to accomplish, of course, is to take your opponent's three-ball shot (what he might think of as his 'insurance' ball, or 'goalie' ball) away from him by pocketing it yourself! This is the first goal. The second goal is to free up that pocket for your own balls. The third goal is to hide the cue ball amongst your own balls, hopefully glueing it to one or more of them so your opponent has to attempt a two- or three-rail kick to get to his own balls (remember, he doesn't have his easy three-ball to shoot anymore). You must also, obviously, carom the cue ball off of one of your own balls and then into his three-ball to make a legal hit. This type of shot is very simple, and advanced players know it well, but it is one of those options average players simply don't see, and is a perfect example of accomplishing several things with one shot.
Another example is a ball-in-hand situation. Your opponent has ran all of his balls but hooked himself on the eight-ball. After his foul, you have ball-in-hand. All of your balls are spread out well except for three balls in a cluster along a rail. Many times a player will attempt a break out shot by slamming a ball into a pocket and sending the cue ball flying into the cluster. This is unwise for at least two reasons: hitting hard makes the balls do unpredictable things, and 'breaking up' the balls at that velocity might very well form other clusters somewhere else on the table.
An option here, depending on how the cluster sits, is to 'tap' the cluster at fairly close range, again accomplishing multiple goals: your cluster is broken (at a manageable speed so you can somewhat control where the balls end up on the table), and you freeze the cue ball in a spot where your opponent has to pull off a three rail kick shot with his cue at a sixty-degree angle just to avoid giving you another ball in hand!
There are countless ways this principle applies, especially is position-oriented games such as eight-ball and one-pocket. Against a skilled opponent, every shot must take into account multiple objectives. On a crowded seven-foot table, an expert player playing eight-ball, or nine-ball for that matter, will not attempt to run his balls until he has everything right where he wants it. This may mean taking care of a cluster, clustering his opponent, adjusting a key ball, etc. I've known a few players who, if they deem it necessary, will, with a wide-open table, play four evil safeties in a row in order to adjust the ball spread. By evil I mean safeties in which my cue ball was frozen to at least one of his balls or a rail, and virtually no legal shot was available.
When playing safe, always take into account all the factors: Where will my balls be after this shot? Where will my opponent's ball be? Is he just going to safety me back?
Also, give yourself leeway. Don't attempt a shot which, if your speed is off just a little bit, your opponent will have an easy run-out. A good benefit of multiple-objective safeties is that even if one of the goals isn't met, the other one probably will be.
Finally, always ask yourself how the shot is benefitting you, not just how it will hurt your opponent. Safety play requires foresight, not just making your opponent shoot a difficult shot.
