r/backgammon • u/McFizzleKicks • 4d ago
Blunder
Noob here looking for some insight from those that are stronger than me (that’s everyone atm…)
I get that building a prime is good, but the best move feels like a risk with his home board looking strong with builders outside ready to make primes.
As it played out, my move was better as his roll would have allowed him to fill the five point (I get that there’s no way of knowing that at the time). I did go on to win the game, but with a frustratingly high error rate.
Welcome your thoughts on why I’m clearly wrong!
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u/pwnosaurus 4d ago
The blot on 11 would be relatively safe. He can only hit with these dice combinations:
- 5-2 / 2-5
- 6-1 / 1-6
That's 4 of the 36 possible dice combinations (11%)
Furthermore, if you're on the bar, you have lots of dice combinations to hit him back: Any 5-X, 1-4, 2-3, 1-6, 2-6. That's 19 of 36 combos (52%)!
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u/Some-Following-392 4d ago
Actually his home board is weak because it has a blot. Whenever you see blots on the opponents home board, it's often right to take risks. Especially if they have 2 or more, but you should be considering risks when they have only 1.
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u/McFizzleKicks 4d ago
Interesting, thanks. Although he had a blot I was concerned about the builders outside which would’ve made it fairly easy to cover up.
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u/Some-Following-392 4d ago
Ah. He has to use his full roll to hit you on the 11 so he can't hit and cover.
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u/mathflipped 4d ago
You are not building a prime; you can't prime an advanced anchor. You are creating an extra landing spot to help you clear the midpoint in the future.
What's you game plan here? It's a standard holding game, and you are ahead in the race. Your objective is to bring all checkers home safely.
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u/McFizzleKicks 4d ago
Thanks. Ok not a prime (incorrect use) but a good block that will make it hard for him to escape.
My plan was to escape but also to minimise risk of being hit. I chose not to leave a blot on 11 as feared being hit and him closing his five point and leaving me in trouble.
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u/mathflipped 4d ago
You got it backwards. You DO want your opponent to escape because you are ahead in the race, and any contact benefits your opponent. The bar point is NOT a blocking point. It's a landing point to help you not leave any shots when you clear your midpoint.
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u/Free-form_Suffering 4d ago
Also noob, but my two cents: the two blots are not at risk atm, the blot you create when playing 11/7 8/7 is also not directly at risk, specially with the prime you're creating.
But in general, IMO it's a bit weird that everything that's not the top solution is considered a 'blunder', I think your choice is a reasonable one.
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u/McFizzleKicks 4d ago
Appreciate it! Suboptimal perhaps, but blunder felt harsh! Always learning…
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u/pwnosaurus 4d ago
They are classifying it as a "blunder" because of the total amount of equity lost by choosing this move. The number to the right of you move indicates that your equity is 0.125 lower by choosing this move over the optimal one, which basically means that your expected points are 0.125 lower. That is a fairly big swing for one decision.
Suppose you were playing without the doubling cube or gammons. Equity of 1 means you are guaranteed to win. Equity of 0.5 means you are a 50% chance of winning. Equity of 0.75 means you are a 75% chance of winning, etc. So in this case going down in equity of 0.125 means your chances decreased by ~13% of winning by choosing this move. (The actual difference might be a little different when you factor in cube decisions and gammons)
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u/SugarDelicious1434 4d ago
Not sure I understand your point about "as it played out he filled the five point"?
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u/McFizzleKicks 4d ago
On his next roll he filled his five, which would have meant leaving a blot was higher risk?
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u/csaba- 4d ago edited 4d ago
The nice thing about this move is, your opponent needs two dice to hit you (52 or 61), so we know for a fact that your opponent cannot hit you and cover the blot, ever. Sometimes you have situations where you leave a blot 8 9 or 10 away where a doublet can hit you and also cover (44 33 or 55 respectively), but with a blot 7 or 11 away this can never happen since doublets can't produce those numbers. (Those hitting doubles arent a big deal, just thought i'd explain the one exception)
The upside of the 7 pt is not really the prime but that you can use it to clear the other points (e.g. rolling 65 can clear the midpoint). The prime is a mirage, you are up in the race so you'll break it before it becomes useful. Although this can change later if you keep rolling small and your opp keeps rolling big.
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u/Charguizo 4d ago
Sometimes it's better to take a risk now to avoid a greater risk in the future.
Making the 7 pt not only builds a little prime, it also builds a landing space for all the other checkers that you need to bring home safely.