So I remembered to bring my headphones with a mic (I ordered the mini mic but it hasn't arrived yet) to the pool hall with me today. I'm kinda sick so my speed were a little low. My average was only 23.78 with my high being 24.91. I've hit 27.56 on the gun in Vegas so hopefully once I'm feeling better I be able to get above that. I can already see this app getting a ton of use from me and my friends.
If you're going to compare Break Speed with a radar gun, there are some things you should know. You may think I'm biased, but I'm going to stick to facts and be completely fair.
Also, most pool players that have ever had their speed tested with a gun should probably follow along with this, even if they don't use Break Speed because it can change the way you think about the gun.
Most people know that RADAR works by timing the difference between how long it takes for signals to be reflected back to the gun.
Now, consider standing on the side of the road pointing a gun straight across the road, waiting for a car to drive through the radar gun's beam. As a car passes through the beam, the car is not getting any closer or further from the gun (it's going completely sideways through the beam), so the signals bouncing off the car back to the gun all bounce back with the same round-trip time. To the gun, the car will appear to be traveling at 0MPH.
Ask any police officer, and they will confirm this - the most accurate result is when they're traveling directly toward or away from you. Any angle you introduce works in the driver's favor (it produces a slower rate of speed.)
When they time a break shot, you can't get the cue ball coming directly at the gun. There will always be some angle because the rack is in the way. When we had our speed tested at the booth in Vegas, they held the gun directly over the head ball of the rack and pointed it at roughly a 45-degree angle down. The cue ball would enter the beam about a foot from the rack.
So if the gun was held at a 45-degree angle, wouldn't it produce a speed at roughly half the correct speed? Not exactly half, but close enough for this discussion. Yet the gun produced reasonable results. How?
I don't know this for sure, but I can imagine that this means that they probably calibrated it with a special tuning fork (which is how you calibrate a radar gun.) This could ~double the speeds produced by the gun to correct for the angle. This will have a negative effect on the accuracy of the result, but there is actually more to it than that.
We now have a human being holding a gun at the end of an extended arm. Watching closely, I saw as much as a 15-degree difference in the way she was holding the gun each time she would record a break speed. This is where the real error is going to come from.
To be fair, Break Speed as a similar problem, in that we rely on you (a human) to set the cue ball position accurately within the application and on the table. This is why we recommend, if you are working on your break and you need absolute accuracy, to break from the spot or from a carefully marked intersection of the diamonds on the table. This way, you can get the most accuracy in placing the cue-ball within the application and on the table. Check our FAQ for more details. With this, you should be able to get extremely accurate results (hundredths of a mile per hour.)
Additional error from radar guns comes from guns that are not properly tuned. Not only do you have to use a tuning fork, but that fork must be struck on a certain kind of surface. For example, the police are taught to strike it on the heel of their shoe. Furthermore, the placement of the radar gun so close to the subject being timed will introduce additional inaccuracy.
So although nobody has yet to complain that the speeds coming from Break Speed don't match the speeds they get from a radar gun, if you have found that to be the case, now you know why.