Casual Player level

What "Casual" 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.

A Casual player is a member whose play sits in the band PR 15.1 to 17.4. On an average decision they give away about three hundredths of a point. That is the strength of somebody who plays for the room and the company as much as for the result: they know the game well enough to make a plan, and not well enough to know which of two plans is right when it is close.

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

Each of the forty Casual 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 Casual members are the same player. One sits near 15, another near 17; 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 Cardozo is not the same as meeting GG Herrera.

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. A Casual member gives away about three hundredths 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: a Casual member starts at 1300, Guru at 2300. On the club's rating scale, that difference gives the Casual member an expected chance of winning of about 24 % in a single game, 12 % in a 3-point match, 7 % in a 5-point match and 4–5 % 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 a Casual member is tuned

The engine underneath every member is the same one: GNU Backgammon, which reads every position at full strength. A Casual 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 a Casual 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

A Casual player's mistakes fall where a human's do at this strength: in the middle game, when there are three reasonable plays and the best one is a matter of timing. In a straight race or a bear-off, where the play is obvious, they are nearly clean — because people are nearly clean there too. They will not make an absurd move; there is a hard ceiling on how much one decision may throw away. And when clearly ahead, they will not suddenly hand you the game with a needless blot. Modest, yes. Fake, no.

The cube at Casual level

Checker play and cube handling are tuned separately, because in people they come apart. A Casual player doubles late and takes a little too much — not as timidly as a Beginner, but the cube is still the part of the game they understand least. Their cube decisions run through the same "sees it slightly wrong" model as their checker play, fitted to how players of this strength really double, take and drop. It is where you beat them.

Is this your level?

If you play regularly, win more than you lose against friends, and have never sat down to study a match afterwards, this is probably where you are. Play here and the matches should be close; the review after each one will tell you which side of close you are on.

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 Casual range and you carry a Casual 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 forty members below are the first field most careers have to get through.