AllieStein and Leelenstein

In last week's post about two world class engine-vs-engine competitions, TCEC Cup 4 Finals & CCC11 R1 Underway, I decided,

Instead of a weekly report on the two competitions, I'll report every two weeks. That rhythm is sufficient to follow the tournaments without having to spend too much time on them. It also allows for an occasional post on the off-week, to go a little deeper into the underlying issues.

In 2017, we saw the AI/NN engine AlphaZero burst into the top rank of chess engines. In 2018, it was joined by Leela. In 2019, as my post TCEC/CCC 2019 Q1-Q3 Summary from a couple of weeks ago revealed, they were joined by AllieStein [playing in the TCEC] and Leelenstein [in the CCC]. It's instructive to chronicle the progress of those last two engines in 2019. Let's start with AllieStein's progress in the TCEC:-

• 2019-03-18: TCEC S15 Div4 Finishes; Stockfish Wins CCC6 • 'TCEC S15 division 3 is currently underway. The two top placed engines in divisions 4a and 4b all met in a playoff, from which the two top engines qualified into division 3. The AI/NN engine AllieStein (Allie + Stein) was one of the two qualifying.'
• 2019-03-25: TCEC S15 Div3 Finishes; CCC7 Starts • 'S15 division 2 is currently underway. The AI/NN engine AllieStein was one of two qualifying from division 3.'
• 2019-04-01: TCEC S15 Div2 Finishes; CCC7 Nears Final • 'S15 division 1 is currently underway; the AI/NN engine AllieStein was one of two qualifying from division 2.'
• 2019-04-08: TCEC S15 Div1 Finishes; CCC7 Final Starts • 'KomodoMCTS and AllieStein finished 1st and 2nd in division 1 to qualify into the premier division with six other engines.'
• 2019-04-29: TCEC S15 Final: SF vs. Leela; CCC8 S1 at 3/4 Mark • 'Among the also-rans, the result of AI/NN engine AllieStein was the most remarkable. Starting the season in division 4, the lowest of the five divisions, it consistently finished in the top-2 for each successive division, eventually qualifying into the premier division. There it tied for 4th/5th with Houdini. [...] AlphaZero was the first AI/NN engine to compete at the level of the traditional engines; Leela was the second; and AllieStein is the third.'
• 2019-09-13: Beyond AlphaZero • 'ScorpioNN and Stoofvlees first survived the [S16] qualification stage, then the two league stages (finishing ahead of another NN engine, FireNNb, along the way), and are currently playing in the TCEC Premier Division. There they were joined by two other NN engines, LCZero and AllieStein.'
• 2019-09-16: TCEC S16 DivP & CCC10 S3 Both Underway • 'The [S16] Premier Division has another week to run. Three engines -- AllieStein, LCZero, and Stockfish -- are currently within a half point of each other, two points ahead of the rest of the field.'
• 2019-09-30: TCEC S16 Final Underway; Leelenstein Wins CCC10 • 'The Premier Division finished with Stockfish, AllieStein, and LCZero at 1st/2nd/3rd, each separated by a half-point. [...] After 22 games in the 100-game final match, Stockfish has a two point lead over AllieStein.'
• 2019-10-14: Stockfish Wins TCEC S16; CCC11 Underway • 'Stockfish beat AllieStein by a final score of 54.5-45.5, more specifically +14-5=81.'

The TCEC provided the first mention of Leelenstein; after that it was all CCC:-

• 2019-03-04: TCEC S14/S15 Interlude; CCC6 S2 Wrapping Up • 'After the finish of [TCEC] S14, while S15 preparation was underway, the site conducted three short competitions. The first event was a 48-game three-way match that lasted a day or so. It finished with the result Stockfish 17.5/32, Leelenstein 16, Antifish 14.5.'
• 2019-03-25: TCEC S15 Div3 Finishes; CCC7 Starts • 'The same [Chess.com] report outlined the plan for CCC7. [...] That makes four AI/NN engines: Lc0, Antifish, Leelenstein and, Allie.'
• 2019-04-08: TCEC S15 Div1 Finishes; CCC7 Final Starts • 'The preliminary event 'Blitz Bonanza' finished with a surprise result. Although Stockfish finished first, it was ahead of three AI/NN engines -- Leelenstein, Leela, and AntiFish -- in that order.'
• 2019-05-06: TCEC Cup 3 Nears QF; CCC8 S1 90% Finished • 'Leelenstein and Antifish will be fighting each other for one of the last two places in the final.'
• 2019-05-13: Leela Wins TCEC Cup 3; CCC8 S1 99% Finished • 'Since the rules specified, 'Top 4 engines advance to final, only two can be from a single, or shared, code-base', Leelenstein beat Antifish for the second qualifying spot in the Leela family.'
• 2019-05-20: TCEC S15 and CCC8 Finals Both Underway • 'In the final stage, with about two-thirds of the games already played, the order of the four engines is Stockfish, Leela, Leelenstein, Houdini. The point spread between each successive place is almost enough to guarantee that this will be the final standing.'
• 2019-07-15: TCEC S16 Starts; CCC9 Finishes • 'CCC9 Gauntlet Final (200 game match); 1) 103.5 Stockfish; 2) 96.5 Leelenstein'
• 2019-09-16: TCEC S16 DivP & CCC10 S3 Both Underway • 'Six engines advanced from the quarterfinals, with Stockfish, Lc0, and Leelenstein finishing well ahead of the others. [...] The 'CCC10 Semifinals' stage is currently underway with the same three engines again well ahead of the other three.'
• 2019-09-23: TCEC S16 DivP & CCC10 Final Nearly Complete • 'Leelenstein and Stockfish finished tied for 1st/2nd in the 'CCC10 Semifinals', thereby advancing to the final match. [...] Of the 200 games scheduled for the 'CCC10 Finals', 190 games have already been played. Leelenstein has a narrow but convincing lead over Stockfish.'
• 2019-09-30: TCEC S16 Final Underway; Leelenstein Wins CCC10 • 'Leelenstein beat Stockfish by a score of +19-15=166 in the CCC10 final.'
• 2019-10-28: TCEC Cup 4 Finals & CCC11 R1 Underway • '[The following chart] captures a portion of the final crosstable for the 'CCC11 Qualification' stage. Only the full results of the first six engines, Leelenstein 1st, are shown.'

Both AllieStein & Leelenstein entered the competitions at the same time and both reached the top ranks at about the same time. Does that tell us something about AI/NN engine development?