Tangent Lines in Pool

Series Summary

The game of pool, or billiards, was developed, like other cue sports, from outdoor stick-and-ball lawn games similar to golf or croquet. Pool was originally played on tables without pockets. Holes were added later, used first as a hazard and later as a means of scoring. The term 'pool' was derived from 'poolrooms,' which were off-track betting facilities where gamblers would 'pool' their money to determine the odds on horse races. These facilities were often equipped with a few billiards tables, and the words 'pool' and 'billiards' soon became interchangeable.

In this free video series, our expert Roger Long will tell you how to position the cue ball in billiards. He'll teach you all about tangent lines and how they affect cue ball positioning. He'll tell you how about topspin, sliding, backspin, and the speed of the spin. He'll even tell you how to avoid scratching the cue ball and work the angle off the rails with spin.

Video Transcript

"In moving on with our knowledge of how to position the cue ball to get it to go certain places, to set us up for other shots. There's something that we have to be well aware of. It's something that isn't quite obvious to most beginners, so we want you to be aware of it right away. What we're talking about here, is we're talking about the tangent line. The tangent line, I don't know if you've ever heard of anything like that before in association with pool, but it's something that advanced pool players talk about all the time. It's also known as the right angle line. So whichever one you want to refer to it as is fine. But, you really have to have knowledge of what the tangent line tells you. First of all, let's define what the tangent line is. We had before; we had our line of travel, the direction we want the ball to go. So if this were our object ball, right here, and we want it to go right to the center of that pocket right there, then our contact point would be right here. So there's our first line, it's an imaginary line, once again. Now, the other line, the tangent line we're talking about is going to be an invisible line that runs along the edge of the object ball, at the contact point and it's going to be at a 90 degree angle to that line of travel. So in other words, this right here would be your tangent line. Doesn't matter where your cue ball is coming from that contact point never changes that line of travel isn't changing, so that tangent line doesn't change. What that tangent line is going to do for us, it's going to give us a guide. It's going to tell us the general direction the cue ball is going to travel after it contacts that ball an comes off that ball. So that's just the starting point. If we had the shot over here for instance then our tangent line would look like this it would be running that way. If we were over here, then tangent line runs like that. All around the table. So we've got our tangent line for our starting point telling us the general direction that a cue ball is going to go after it comes off of that object ball."