Estimating Percentages

Colin Colenso

AzB Silver Member
Silver Member
I've developed a new game which is quite challenging and entertaining.

One aspect I want to include in videoing the game is to make estimates on the probability of completing an innings successfully. Hence, I'd like some of you to provide some percentage estimates based on the challenges below.

The challenge for each player's inning is that they get 2 shots to pot the ball number that they have been alloted. They may pocket any ball on their first visit, but on their second visit they must pocket their alloted ball.

Below is a typical layout, starting from a pretty good position, with 4 balls in reasonably makeable potting positions. Balls numbered 2, 4, 10 and 12. It's likely the player will choose one of these for the starting shot.

I've provided 3 possible ball options for the second shot, circled in yellow, numbers 7, 8 and 9.

So what I want you to do is to estimate the probability for an A+ player (lets say mid pro playing in their mid form) to make their alloted ball from this position.

i.e.: What percentage of the time from this position could a mid-pro player pocket the 7 ball within his 2 shots?

The 8 ball?

The 9 ball?

Note that the player must successfully make the first shot to continue on to the second shot.

Please give your own estimates, don't just agree with others. I want to see how much variation people have in their estimations. There is no right or wrong answer....unless of course that table was laid out and a bunch of pros took a shot at it. This would have to be a first up attempt. Obviously with practice any percentages would increase.
 

Attachments

  • 2shotpercentages.JPG
    2shotpercentages.JPG
    36 KB · Views: 301
Let me add, that we should assume the table is 4.5" pockets, newish cloth.

btw. If you want to explain how you'd attempt each option, that would be good.

Colin
 
Last edited:
My guesses...

For A+ player...

9 ball => 85%
7 ball => 75%
8 ball => 60%

-----
For me...

9 ball => don't bet on it
7 ball => don't bet on it
8 ball => don't bet on it
 
I'll go first. The 7 60%, the 8 50% the 9 70%. If I had to play the 8 I'd probably bank the 1, for the 9 take the 10 and for the 7 I'd probably take the 12.

gr. Dave

edit: Guess some people type faster.
 
Double-Dave said:
I'll go first. The 7 60%, the 8 50% the 9 70%. If I had to play the 8 I'd probably bank the 1, for the 9 take the 10 and for the 7 I'd probably take the 12.

gr. Dave

edit: Guess some people type faster.


I was thinking on the 8 you could play the 4 in the corner and come around for the 8 in the side.
Two different ways to accomplish the same thing but I am much more likely to make a cut than a bank.
 
Koop said:
I am much more likely to make a cut than a bank.

I'm not, hence the nickname:D
Seriously though I prefer being able to put some power into the CB, fine cut shots are not my cup of tea.
 
Koop said:
Does the 7 go past the 11 and 13?
Let's assume it's possible, but barely. Say the 7 would pretty much have to hug that rail on the way past. Hence, looks like a low % shot to me.

Colin
 
my explanation

jsp said:
For A+ player...

9 ball => 85%
7 ball => 75%
8 ball => 60%
9 ball => 10 in the corner with follow, then 9 in side. Easy enough.

7 ball => 2 ball is too steep an angle to hold position for the 7 in the top left corner. 7 ball may have clear path to top right corner, but making the 2 ball combined with getting position on the 7 and making the 7 in the top right would make things more difficult. Stun the 12 ball in the corner (99.99% probability) and opt for the tough shot down the rail. I figure a pro would make that shot 3 of 4 times.

8 ball => Must use the 4 for position, but 4 is too steep an angle to hold position for the 8 in the bottom left. If you try to hold position, you risk the 4 not making it to the pocket. You'd have to go two rails around the 5 and pocket the 8 in any of the 3 top pockets. Because you have 3 available pockets, an A+ player will probably make the 8 from that position more times than not.
 
Interesting estimates guys, thanks.

For what it's worth, here are my own estimates and methods:

7-ball: 85%. Roll through 6" on the 12 ball and make the down rail cut.

8-ball: 55%. Make that toughish shot on the 4-ball trying to get in between the 1 and 5 balls for a shot in the center or corner pocket.

9-ball: 90%. Though a bit knuckeld up on the 4-ball, should be able to make that 10-ball into the corner and roll through for perfect position on the 9-ball into the center bag.

Colin
 
In case you're interested, what I plan to do is shoot a video of a match under these rules and in post production I'll insert a graphic into the video to show the percentage chance estimate of making the 'on ball'. A bit like the percentage stats we see in poker.

But the percentage will be an average based on the estimates of 5 experts, who will have received screenshots of all the match shots. Also, a telestrator could be used to indicate the prefered choice of shot.

In trials of the game, making the 'on ball' within the 2 shots is about a 60% probability. It often requires making some pretty impressive potting and positional shots....something that most game formats lack I believe.

Colin
 
Last edited:
Colin Colenso said:
In case you're interested, what I plan to do is shoot a video of a match under these rules and in post production I'll insert a graphic into the video to show the percentage chance estimate of making the 'on ball'. A bit like the percentage stats we see in poker.

But the percentage will be an average based on the estimates of 5 experts, who will have received screenshots of all the match shots. Also, a telestrator could be used to indicate the prefered choice of shot.

In trials of the game, making the 'on ball' within the 2 shots is about a 60% probability. It often requires making some pretty impressive potting and positional shots....something that most game formats lack I believe.

Colin

I am very interested. The only difference in your percentages is that I would think the 8 ball is easier than the 7. Those cuts, hugging rails, can sometimes be ify for me. I agree the 9 is the easiest but would probably flip-flop your odds on the 7 and 8.
 
7ball: I think I would use the 10 to get to it. It looks like you have enough angle to slide over between the side pocket and the 11/15 balls. Play more towards the 11/15 and a little short of ideal to avoid possible snooker/scratch.

8ball: Use the 4 and go two rails towards the one. If you come up a little short you could go in the side.

9ball: Use the 10 with soft follow. Then 9 in the side.

I Think the 8 ball is the hardest sequence with the possiblity of a hook. Maybe 50/50 for me. Then the 7 because it will likely be a tough shot. The easiest being the 9. A pro should get out on the 9 95%.
 
I'm not sure if I totally get this but I'd say

10 in the corner with mid to upper right english then take the 7 down the rail. 85%

For the 8 ball I take the 4 first and then two rails for the eight in the side. 60%

For the 9 I take the 10 as well and high right english and float the cue ball past the 9 twords the foot rail and take the 9 in the side. 85%

Dang you guys are fast. 5 replies just while I was typing this lol
 
Last edited:
I completely agree with the 7 ball and 9 ball. Although for the 8 ball, the straight pool player in me would actually try and bump the 5 or 1 ball. I say this becasue by bumping those balls will give me a better predicted outcome for a pocket to shoot the 8 in, instead of trying to stop the rolling of the cue ball on the short side of the zone. Bumping the 5 would give you either of the foot rail pockets and possibly the top side pocket. Bumping the one is an alomst lock for the cornere where the 4 went.

As far as percentages, I am inclined to think if the angle will allow me to bump the 1 and 5 without too much difficulty, this percentage would increase some.

If we are talking A-Player, I would think:

9 = 90%
7 = 85%
6 = 70%

Anyway fun to participate.
 
Koop said:
I am very interested. The only difference in your percentages is that I would think the 8 ball is easier than the 7. Those cuts, hugging rails, can sometimes be ify for me. I agree the 9 is the easiest but would probably flip-flop your odds on the 7 and 8.

That's why it's probably best to take an average of opinions. Some guys will almost never miss that down the railer if the angle is not too acute, but for others it's a tougher proposition.

Also for your interest, there is a twist in this game that I didn't mention. Bluffing! Say for example you are 'on' the 11 ball, maybe a 10% chance at best. Instead of attempting it, you can choose to bluff. Let's say you pretend you're on the 7-ball and deliberately miss it. You lose a life, but an incoming player has the option to pocket a shot you've missed as an alternate 'on ball', but he must correctly nominate if it is your 'on ball'. If you've fooled him, and he calls the 7-ball as yours, then he loses a life and you gain his life.

So when faced with difficult shots, bluffing becomes an option.

The viewers will know when players are bluffing, but the players must look for tells.

The rules are a bit complex, but not as complex as Texas Holdem. After watching a few racks, viewers should have pretty much worked out what's going on, but it could take a while for a player to become expert in knowing when and how to bluff, and for opponents to become expert in reading tells.

This is a game where players play in a ring type format, and they must be paying close attention to the moves and sideway glances of all their opponents. Earl wouldn't get too far staring into his lap between visits.:p

Colin
 
Collin sound slike fun. Do they draw peas for ball number or what? And can they play safe if they think they know what someone else ball is? What happens when all the balls are made or if someone make theirs?
 
Donovan said:
Collin sound slike fun. Do they draw peas for ball number or what? And can they play safe if they think they know what someone else ball is? What happens when all the balls are made or if someone make theirs?

Yeah, they draw peas, or cards, like with what we call Kelly Pool, so each person has their own secret number. But Kelly Pool doesn't work with elite players as they can shoot until they miss, which makes it too easy.

I had to play with quite a lot of rule variations before settling on something that works well and prevents unwanted safety play and to get the right amount of bluffing, probably about 1 visit in 5 or less will be a bluff, but when bluffing pays off, it creates a lot of fun.

The players can only guess what the other players are on and can only call them for being 'on' a ball that they have attempted and missed.

There is no real incentive for safety play, as I can figure, as it is a ring game format and even when it plays down to 2 players, there is not much value in a safety as the incoming player can shoot at any ball first up, so most the time it is hard to leave them no shot better than a 50% chance. If a ball is really hard to get onto and make, it's better to bluff. However, a player has some incentive to leave the CB as safe as possible after their second shot.

I can't announce all the rules at this time, but I think it will be a fun and challenging game for reasonable level players and a great game to watch on video, as the audience has the advantage of knowing all that is going on, getting the chance to enjoy watching how players bluff, how well opponents pick their tells and also they'll get to see a lot of advanced shots in the mix.

Another aspect that will be enjoyable is seeing a player make his 'on ball' when the panel of experts rate the shot at say 30% or lower. These efforts will be like mini-victories.

Colin
 
Cute 2 roll into and lay on the 15-100%
Shoot 7 12 o'clock high roll to 2 lower balls down table-85%+
Angle from lower balls determines path to other solids by the 8-85%
Angle from lower ball to get to the other solids 70%
 
Colin Colenso said:
Yeah, they draw peas, or cards, like with what we call Kelly Pool, so each person has their own secret number. But Kelly Pool doesn't work with elite players as they can shoot until they miss, which makes it too easy.

I had to play with quite a lot of rule variations before settling on something that works well and prevents unwanted safety play and to get the right amount of bluffing, probably about 1 visit in 5 or less will be a bluff, but when bluffing pays off, it creates a lot of fun.

The players can only guess what the other players are on and can only call them for being 'on' a ball that they have attempted and missed.

There is no real incentive for safety play, as I can figure, as it is a ring game format and even when it plays down to 2 players, there is not much value in a safety as the incoming player can shoot at any ball first up, so most the time it is hard to leave them no shot better than a 50% chance. If a ball is really hard to get onto and make, it's better to bluff. However, a player has some incentive to leave the CB as safe as possible after their second shot.

I can't announce all the rules at this time, but I think it will be a fun and challenging game for reasonable level players and a great game to watch on video, as the audience has the advantage of knowing all that is going on, getting the chance to enjoy watching how players bluff, how well opponents pick their tells and also they'll get to see a lot of advanced shots in the mix.

Another aspect that will be enjoyable is seeing a player make his 'on ball' when the panel of experts rate the shot at say 30% or lower. These efforts will be like mini-victories.

Colin

I can't wait for you to come up with a name for this Colin.

Deception
Pot 'n' Bluff
N.U.T.S. (Never Underestimate Two Shots)
Stayin' Alive
Life or Death
Colenso Bluff 'em
Mine and Yours
Wanted Dead or Alive...But Mostly Dead
Who's Your Daddy?
Kiss my butt, you shot the wrong ball, BE-ATCH!

Ok, well some of these were ligit...:D

Good luck with this bro!
 
Back
Top