Questions:

- What does the rank 1000 mean?

- What does the score 31744 mean?

- Why all moves have the same rank (1000) and score (31744), both DTZ and WDL? What extra information DTZ has added, compared with WDL?

- The winning line starts with move Rc2, how to get/compute that 1st move (Rc2)?

- There is another winning line starts with Rg6 and it is as good as Rc2's one. Is there any way to find it out?

Thanks

Code: Select all

```
[Event ""]
[Site ""]
[Date "??"]
[Round "-"]
[White "Syzygy"]
[Black "Syzygy"]
[Result "1-0"]
[FEN "K7/8/2R5/8/8/8/8/7k w - - 0 1"]
[WDL "Win"]
[DTZ "21"]
[WinningMoves "Ka7, Kb7, Kb8, Rc1, Rc2, Rc3, Rc4, Rc5, Ra6, Rb6, Rd6, Re6, Rf6, Rg6, Rh6, Rc7, Rc8"]
[DrawingMoves ""]
[LosingMoves ""]
1. Rc2 Kg1 2. Ka7 Kf1 3. Kb6 Ke1 4. Kc5 Kd1 5. Rh2 Kc1 6. Kd4 Kd1 7. Ke3 Kc1 8. Kd3 Kb1 9. Kc3 Ka1 10. Kb3 Kb1 11. Rh1# 1-0
17 moves returned from DTZ probe
Ka7 rank = 1000 score=31744
Kb7 rank = 1000 score=31744
Kb8 rank = 1000 score=31744
Rc1 rank = 1000 score=31744
Rc2 rank = 1000 score=31744
Rc3 rank = 1000 score=31744
Rc4 rank = 1000 score=31744
Rc5 rank = 1000 score=31744
Ra6 rank = 1000 score=31744
Rb6 rank = 1000 score=31744
Rd6 rank = 1000 score=31744
Re6 rank = 1000 score=31744
Rf6 rank = 1000 score=31744
Rg6 rank = 1000 score=31744
Rh6 rank = 1000 score=31744
Rc7 rank = 1000 score=31744
Rc8 rank = 1000 score=31744
17 moves returned from WDL probe
Ka7 rank = 1000 score=31744
Kb7 rank = 1000 score=31744
Kb8 rank = 1000 score=31744
Rc1 rank = 1000 score=31744
Rc2 rank = 1000 score=31744
Rc3 rank = 1000 score=31744
Rc4 rank = 1000 score=31744
Rc5 rank = 1000 score=31744
Ra6 rank = 1000 score=31744
Rb6 rank = 1000 score=31744
Rd6 rank = 1000 score=31744
Re6 rank = 1000 score=31744
Rf6 rank = 1000 score=31744
Rg6 rank = 1000 score=31744
Rh6 rank = 1000 score=31744
Rc7 rank = 1000 score=31744
Rc8 rank = 1000 score=31744
```