Today we’ll take a look at a couple of additional (and useful!) opening book options which you can toggle “on” or “off” in ChessBase 11.
To access these options, right-click in an empty spot in a ChessBase opening book display (as described in our previous two blog posts) and select the “Properties” command:
…which will bring up the following dialogue:
The first option we’ll look at is the “Retro moves” box. Obviously, to activate it you’d just click the box to check it and then click the “OK” button.
Here’s an example of how it works. After the moves 1.e4 e5 2.Bc4 Nc6 3.Nf3 we’d see the following position:
This is a pretty common position; in fact, it’s the start of the Giuoco Piano. But we’ve reached this position by an unusual move order – normally we’d get here by playing 1.e4 e5 2.Nf3 Nc6 3.Bc4. The “Retro moves” function can alert us to this transpositional possibility. Here’s what the opening tree looks like with “Retro moves” activated:
We see all of Black’s replies listed as usual, of course, but we also have two additional entries down at the end of the list: a couple of White’s moves. This indicates that there are two prior board positions which lead to this position, hence that there are two ways to get to where we are now. The current board position (in the illustration above) occurs in two ways: after White has played 2.Bc4 or 2.Nf3. Since we played the moves 1.e4 e5 2.Bc4 Nc6 3.Nf3 to get here, we can see by the number of games that we’ve been on “the road less taken” and that 1.e4 e5 2.Nf3 Nc6 3.Bc4 is the more commonly played variation.
The “retro moves” toggle is very handy for finding opening transpositions; these are really good to know, especially when you frequently find yourself playing against people who learn openings by memorizing move orders instead of the correct method – by recognizing positions and knowing their underlying themes and principles.
The second opening book tweak is “Unplayed transpositions”, a toggle which allows the opening book display to “fill in gaps” and display moves which weren’t actually played but which lead to known positions from the opening book.
Here’s an example of “Unplayed transpositions” in action. Continuing our variation by a couple of moves: 1.e4 e5 2.Bc4 Nc6 3.Nf3 Nf6 4.d3 Be7, we come to this position:
With “Unplayed transpositions” checked, we have a look at the opening tree and see this:
Notice the presence of two White moves in half-tone (grey). These are moves which weren’t actually played from this position in the games from which the opening tree was created. But both of these moves do lead to positions which are in the opening tree – these “extra” two moves are displayed here because we’ve checked “Unplayed transpositions”. So, for example, after the move 5.Bb5 (one of the moves marked as an unplayed transposition), we see this in the opening book display:
Note that the position after Black plays 5…d6 is a known position, which occurs in five games. But Black himself has two unplayed tranpositions, one of which is 5…Bc5 – a position which appears in 672 games. If we make that move on the chessboard, we’ll see this:
…which indicates (both by the numbers of games and the predominance of bold face moves in the list) that we’ve transposed back into the Giuoco Piano proper. And we’ve learned about these transpositions solely because we had the “Unplayed transpositions” toggle cheked “on”.
Note that both of these ChessBase 11 opening tree toggles have very similar functions: “Retro moves” shows us transpositions from previous board positions, while “Unplayed transpositions” shows upcoming transpositions. Both functions also have a similar purpose: to show us new (and often very devious and tricky) move orders which get us to familiar board positions – and this may very well provide us with a leg up on our chess opponents.
Have fun! – Steve Lopez
Chessplayers who have purchased their ChessBase brand software from USCFSales can receive free technical support and advice on their purchases straight from me; just shoot me an e-mail (email@example.com), but please remember to include the USCFSales order number from your ChessBase software purchase. – Steve
Copyright 2011, Steven A. Lopez. All rights reserved.