Advanced Player level

What "Advanced" means here

Every member of the club carries a Level of Play, and the level is not a mood or a slider. It is a measured playing strength, expressed in the number the backgammon world uses for exactly that: PR, the Performance Rating. PR is simple to state. Take every decision a player makes in a match, ask the engine how much each one cost compared with the best play, add it up, divide by the number of decisions, multiply by 500. Lower is better; zero is perfect.

An Advanced member's play sits in the band PR 7.0 to 8.6 — roughly a hundredth and a half of a point per decision. This is a strong player: the kind who wins club championships and reaches the later rounds of open tournaments. They rarely make a move you could point at; their losses come from a handful of close decisions a match, and from the cube at awkward scores.

Why a target, and why not every Advanced member plays the same

Each of the 175 Advanced members has a target PR of its own inside that band. The target is what that member is tuned to average over many matches — not a promise about the next one. Two things follow.

First, no two Advanced members are the same player. One sits near 7, another near 8.5; one is a little sharper on the checkers, another a little looser with the cube. Each was given its own fixed sharpness within the level, so that meeting GG Marxer is not the same as meeting GG Davis.

Second, a single match will swing above and below the target, for a member exactly as it does for you. A match full of easy decisions produces a clean PR; a match full of close ones punishes everybody. The level holds as an average, and nothing is done to force one match into the band — no correction, no "making up for it" after a good game, no error budget being spent. That was tried in an earlier build and taken out, because people do not blunder on a schedule and neither should they.

How far from the top

The club's strongest player, GG Guru, plays the engine's best move every time: PR 0. An Advanced member gives away roughly a hundredth and a half of a point on every decision that Guru does not. Over a match that gap tells — but it does not decide everything, because the dice still exist.

Put in rating terms: an Advanced member starts at 1700, Guru at 2300. On the club's rating scale, that difference gives the Advanced member an expected chance of winning of about 33 % in a single game, 23 % in a 3-point match, 18 % in a 5-point match and 14 % in a 7-point match. The longer the match, the less the dice can do for the weaker player. Those are the odds against the very top of the club; against members of the levels below, they turn around.

How an Advanced member is tuned

The engine underneath every member is the same one: GNU Backgammon, which reads every position at full strength. An Advanced member does not get a weaker engine. What changes is how the member looks at what the engine sees: through a little noise, so that when two plays are close, the wrong one can look right. How much noise, and how often the member is sharp rather than careless, is set for the level and then adjusted per member.

The settings were not guessed. They were fitted to how real people at this strength actually err — around 200,000 decisions by approximately 100 real players, from world class down to PR 15.9 — and then confirmed in engine-graded test matches before the level shipped, played by hand after that, and re-measured every time the cast changes — by the time the doors open, every level will have thousands of graded games behind it. When an Advanced member plays like one, that is because the measurement said so, not because somebody thought it looked about right.

Where they go wrong — and where they don't

An Advanced member's mistakes are hard to see without the engine. They fall in the difficult positions — back games, holding games, the decision whether to break an anchor — and they are small. Races, bear-offs and clear positions are essentially clean. There is a hard ceiling on how much any one decision may throw away, and it is a low one at this level.

The cube at Advanced level

Checker play and cube handling are tuned separately, because in people they come apart. An Advanced member handles the cube well in money-game terms and loses a little at match scores where the theory gets subtle — the take at 2-away, the redouble with a gammon in the air. Their cube decisions are fitted to how players of this strength really handle it. Beating them is no longer about waiting for a mistake; it is about making fewer.

Is this your level?

If you have a rating you are proud of, study your matches, and lose to strong players narrowly rather than badly, this is where you belong. Play here and the review after each match becomes the most useful thing on the site.

Your own level is not a label you pick. When you start, the badge beside your name says provisional. As your career goes on it fills in with your average Level of Play, measured the same way the members are: play in the Advanced range and you carry an Advanced badge; play better, and it moves. Try one level below yours for pleasure, and one above it to learn.

Beat them, and they are yours

In Career Mode, beat a member in a tournament or a league and they are unlocked for good — on your account, across every career you ever start. From then on you can sit down with them for a friendly whenever you like, or just say hello. The 175 members below are the largest strong field in the club.