R-Mobility
Goal of reset-mobility is to achieve a position after last pawn/capture move where you opponent has as few legal moves available as possible, while not being in check is counted as an additional 0.5 moves.
Less legal moves, worse scoring. Being in check is considered worse than not being in check.
- Mate is 0 legal moves and in check and thus worst possible result for side being mated and best result for side doing mating.
- Stalemate is 0 legal moves and not in check and thus 2nd worst possible result for side being stalemated and 2nd best result for side doing mating.
- 1 legal move in check is 3rd result.
- 1 legal move not in check is 4th result and so on.
Short syntax for goal is Gn.m where n is number of legal moves and m is 0.5 if not in check and - if black wins.
- mate = G0.0
- stalemate = G0.5
- 1 legal move in check = G1.0
- 1 legal move not in chek = G1.5
If win is for black, then - as added to front: -G8.5
For reset mobility (r-mobility) only positions since last pawn/capture move in the game are considered.
If used for tiebreak purposes, then points decide tournament as usual and is 100% compatible with both FIDE and ICCF rules except for tiebreak calculations unless added to the end of current tiebreaks. In this case 1st (additional) tiebreak is number of times stalemating opponent - number of time being stalemated by opponent. 2nd tiebreak same, but for G1.0 result, 3rd tiebreak for G1.5 result, etc..
Basic endgames
KPvK
| |
| Position after 1. Ke6 |
Mate or stalemate unless pawn can be captured. Diagram for common stalemate result.
KBvK
| |
| Position after 1. Bf5 |
Usually G1.5, example game:
1. Bf5 (diagram)
Subgoal is to get positions where king is forced further towards edge.
Game continues with
1... Kh5 2.Kf4 Kh6 3.Kg4 (diagram)
Now black king as only 1 legal move and is not in check (G1.5).
Players can continue game until 3-fold or 50-more rule, but unless black blunders, white will never achieve better result like stalemate and thus players might as well agre on game result here.
| |
| Position after 3. Kg4 |
Stalemate also possible if opponent king near any corner and other king at suitable position enough near.
1.Kf6 (diagram) Kf8 2.Bd7 Kg8 3.Be6+ Kh7 4.Bf7 Kh8 5.Kg6
| |
| Position after 1. Kf6 |
KNvK
| |
| Position after 1. Nd5 |
Usually G3.5 (diagram) but G1.5, G2.5 and stalemate are possible depending position and sometimes rarely G2.0, G3.0 and G1.0.
KvK
| |
| Position after 1. Ke5 |
Usually G5.5, example:
1. Ke5 (diagram) Kg6 2.Ke6
3-fold will soon follow without neither side being able to improve on result.
G3.5, G8.5, G2.5, G1.5 and G4.5 results also possible depending on position.
With G8.5 or -G8.5 position (diagram) if either side tries to go closer to other king, will then lose to G5.5, for example in diagram position after
1.Kd5 Kf5
white has 5 legal moves and thus black wins game with -G5.5.
| |
| Position after 1... Kxg5 |
Thus both players have to keep distance and 3-fold follows soon and result stays at -G8.5.
KNNvK
Stalemate unless knight can be captured or mate in 1 is available.
Whole game mobility
For whole game mobility all positions in game are included. 2-5 piece tablebases have been generated for wg-mobility and longest records and statistics are available at [1] R-mobility is often same, but there are crucial differences and some games are longer and more natural for r-mobility.
