by Steve Lopez

One of the cool new features of the Classic Shredder6 interface (mentioned in previous ETN issues) is the triple brain analysis feature. This works similarly to Infinite Analysis mode in the standard interface, but with a twist: two engines analyze a position and a third engine (called the "triple brain") acts as arbiter and uses the analysis of the other two engines to determine what line of play is best in that position.

Note that this feature isn't available in the standard Fritz7/Shredder 6 interface -- it's a feature of the Classic Shredder6 interface. For instructions on how to install that interface, see the ETN issue for February 3, 2002.

Triple brain is ridiculously simple to use. First, load a game and go to the position you want to have the triple brain analyze (or else set up a position from scratch). When you have the position on the board, go to the Mode menu and select "Triple brain" (or hit CTRL-B on your keyboard). This brings up the engine selection dialogue for triple brain:

Single-click on the engine you want to load (to highlight it) and then click "Load". This loads the first of the two engines. You'll see the analysis pane for the new engine appear at the bottom of the screen, along with the pane for the engine you already had loaded, plus a third pane for the triple brain. If you want to change the engine that was already loaded, single-click on the box containing that engine's name, and a "Change engine" dialogue appears. For example, in the graphic below, I had Shredder6 loaded and I chose Solid Shredder as the second engine:

I want to change Shredder6 to Gambit Shredder, so I just click directly on the box reading "Shredder6", choose Gambit Shredder from the "Change engine" popup, and click "Load":

Note that when you choose an engine from either of these dialogues, you'll also get a popup asking you what size to set the hash tables. See last week's ETN (February 24, 2002) for details on setting a hash table size.

Once you've selected your two engines, go to the Mode menu and select "Analysis" (or hit CTRL-A on the keyboard). You'll see the analysis start in all three engine panes. The triple brain pane will choose which analysis it considers "better" and display that analysis in its engine pane, along with the name of the engine that generated that analysis.

Let's look at an example of this in action. I decided to analyze an interesting position (described as "unclear" by Gabor Kallai) that occurs after the following moves:

1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nc3 e6 5. g4 Bg6 6. Nge2 c5 7. h4 Nc6 8. h5 Bxc2! (instead of the "normal" ...Be4) 9. Qxc2 cxd4 10. Nb1 Rc8 11. Qa4 Qd7 12. Na3 Nxe5 13. Qxd7+ Kxd7 14. Nxd4 Nxg4

After inputting the moves, I hit CTRL-B and selected Solid Shredder, then changed Shredder6 to Gambit Shredder (as described above), since I wanted two engines with widely varying styles to analyze this unusual gambit position. Then I hit CRTL-A to start the analysis. After a minute and forty-five seconds, and a full eleven-ply search by Gambit Shredder, I saw this in my three engine panes:

If you follow the analysis, you'll notice that Gambit Shredder develops an attack by Black that gets beaten back by White. Solid Shredder shows aggressive moves for both sides, but still indicates an advantage for White. Since it's White's turn to move and Gambit Shredder shows a bigger plus for White, the Triple Brain chooses to go with Gambit Shredder's analysis at the point at which I stopped the engines.

So how does this differ from running two or more engines simultaneously in the Fritz7 or ChessBase 8 interfaces? The Triple Brain itself is what makes the difference. In the other programs mentioned, you can run multiple engines in parallel, but nothing indicates which analysis is preferred in that position; you have to evaluate each line of play yourself to decide on a preference. In the Classic Shredder6 interface, the Triple Brain acts as the "arbiter" and determines which engine's analysis works better in that position.

Does this mean that you should blindly follow the Triple Brain's advice? Of course not! Long-time ETN readers know that I'm a big advocate for thinking for oneself (see the "Learning a New Opening" series from last year). While chess engines are strong chessplayers, they're not "divine oracles" that always provide the "perfect" answer. A lot also depends on your personal preferences; I enjoy gambits and tactics, so a positional engine's analysis might not fit my personal style of play. On the other hand, there are many positions in which a slower positional approach might be called for. So the best thing for me (or any chessplayer) to do would be to view the recommended lines of play, think about what I'm being shown, and decide which variation works best for me. While all of us can certainly do this with the parallel engine analysis feature in the other interfaces (and, by the way, this parallel analysis is also available in the Classic Shredder6 interface), the Triple Brain provides us with additional guidance and input -- an extra signpost along the road, pointing us in the right direction.

Until next week, have fun!

You can e-mail me with your comments, suggestions, and analysis for Electronic T-Notes.