The 50 move rule shouldn't exist!

So how exactly would the progress be calculated with the tablebase?

Definitely repetition obviously. That's the most basic draw. 50 move rule Probably, but it's not like most people pay attention to the number of moves anyway.

For any position a DTM tablebase will tell you whether it's a White forced win, a Black forced win or a theoretical draw (i.e. not a forced win for either side). If it's a forced win for either side it will also tell you the DTM (distance to mate) i.e. the lowest number of moves in which the winning side can guarantee mate however his opponent plays. (So when you see a correct "White to play and mate in 3" puzzle the DTM tablebase will evaluate the position as a White forced win with a DTM of 3. Note that I'm assuming (as the tablebase does) that the side to move is a component of the position. 

The DTM tablebases ignore the 50 move rule so they evaluate some positions as won that can't be won if the 50 move rule is in effect. This is what we actually want.

Progress would be calculated by comparing the tablebase evaluation and DTM for the position when the move count for the rule was last 0 (PZ) with those of the position (PC) at the time of the claim. The move count would be set to 0 first when the number of pieces on the board fell below eight and thereafter when any "no progress" claim were made.

I'll denote the evaluation of a position P returned by E(P) with possible values W (White win), B (Black win) or D (draw) and the DTM for the position as D(P) with a natural number as the value.

In the event of a claim by Black progress by White would be deemed to have been made if and only if any of the following conditions were met.

1. E(PZ)=B and {E(PC)=D or E(PC)=W}

2. E(PZ)=D and E(PC)=W

3. E(PZ)=E(PC)=W and D(PC)<D(PZ)

4. E(PZ)=E(PC)=B and D(PC)>D(PZ)

If progress were deemed to have been made by White the "no progress" claim would fail. The game would continue with PC as the new PZ and the move count for the claim would be reset to 0. If progress were not deemed to have been made by White the "no progress" claim would succeed and the game would end in a draw. 

The same would apply in the event of a White claim with B and W interchanged. 

Cool

But the no progress rule should still be based on 100 moves instead of 50. Otherwise, I agree with your method and should try to convince USCF and FIDE to implement this.

I dunno, just a better figure

They'd have to make sure the tablebases have no glitches lol

The lol is no laughing matter. The Nalimov and Lomonosov tables are believed to be glitch free but several incorrect EGTBs with non DTM metrics have been published. See http://galen.metapath.org/egtb50/ .

Sounds Good

I'm still not completely happy with it though. I don't like my 39½ and I think it might be better to retain zeroing the move count on irreversible moves. But I need to think about it a bit more before posting anything specific.

OMG, just make it 100 already. Who cares if it's exact.

Your over analyzing it MARattigan.

Thanks for the info, but they probably get thousands of contacts a day. They should change the rules. The endgame is where u need time to calculate.They worry about games going on too long, yet they make the time control 6 hours and have 30 second increments. Makes sense. 

They should also have a rule where if u have only 1 legal move, u have to make it immediately, because that's the move that will be made, so there's no point in waiting.

They give each player up to 3 hours, and u don't need 90 minutes to make 40 moves. They don't know that it will drag out some games for hours and hours.

A time rule would be up till a certain point before the next round, say a half hour before, given that whether 40 or 250 moves were made by then, the game would still have to end by then regardless.

My point is if they are so worried about games taking too long, then don't make it possible to have 5-6 hour games.