Alliance vs. Engines Pt.2 endgame analysis (move 44)

I just got news of black's next move: 43...Rd3, as expected.

Here's the present situation on the board:

Let's plan on deliberating till the end of the weekend (Sun night, wherever you are in the world) at most, and then voice our choices here, so I can communicate the team's decision to Jorg shortly thereafter.

I know we anticipated black's present move, so reusing some of our analyses and ideas will be of value here; I recall at least two teammates whose plans called for activating our rook and going into black's back (7th rank) to chase both pawns and king.

Let the discussions and analyses begin!

in previous move forum I already posted the sequence I'm offering here just as a basis for starting a discussion:

43.g4Rd3

44.Ra1...Rxh3

45.Rb1+...Kc4

46.Rb7...Rf3

47.Rc7+...Kd4

48.Rd7+...Kc5

49.Rc7+...Kd6

50.Rxg7...Rxf2+

51.Kb1...a2+

52.Ka1

I'm not sure of course that bringing our R on 7th rank could lead us to a draw whilst I'm afraid instead that keeping it on 2nd/1st we would play the mouse vs a cat

do we want to lose the h pawn?

I agree.  The longer our rook stays on a2, the longer we'd be playing with a rook down, which is not a promising proposition.  To get it out we need to either maneuver the rook via Ra1 and then along the 1st rank (as many teammates have shown in sample lines), or else we need to move our king out of the 2nd rank to create space for the rook...

The second option (moving away our king), however, loses after 44.Kc1? (or 44.Kb1? Kb3 -+) Kb3 45.Re2 Rxh3 46.Rxe4 Rh1+ 47.Kd2 a2 48.Re3+ Kb2 -+

Therefore, we only have the option for direct rook activation via 44.Ra1.

Ra1

If there are other teammates who wish to express their thoughts, please do it within the next several hours; I plan to let Jorg know our move choice before I go to bed tonight (in ~8 hours or so, I assume).

The so-far unanimous choice is 44.Ra1, based on what several of us have expressed in the above messages.