『原文出处』
http://othellogateway.com/othello/blog.php?p=248
『作者』Olli Makkonen & Ben Seeley
Opening strategy
Filed under: Strategy Openings— Ben Seeley @ 1:10 am
[Please note that there are three new posts today.]
[This particular post was published in the Scandic Othello mag a couple of years ago or so.]
Opening strategy, different approaches
This article is about preparing openings for tournaments. The reader should be familiar with the terms Wzebra, Thor database, Opening book, etc.
The competition gets tougher every year. More players are playing the game, but a major factor in the increase in top skill levels is the tools we now have at our disposal. Chief among them being Wzebra. With the use of Wzebra, top players nowadays don’t just have brilliant midgames and endgames, they also have a huge amount of opening positions in their heads.
Basic strategy
The primary goal in the opening is to get your opponent out of book before you are out. That ensures you a good start in the game, because as long as you are playing the game from your memory, you can’t make any mistakes (so long as your memory is accurate for what you want to do). There are two paths in getting your opponent out of book: knowing the common opening even better than he/she does, or surprising them with a variation he/she is not familiar with. Or you can compromise and play a bit less surprising but less known common opening. Either way, the idea is that you have to know it better than your opponent does.
Taking the first approach takes a lot of time and effort. You don’t just need to know the best line by Wzebra, but also all common variations. And if your opponent also knows the opening well, it might lead to long book games. An example of someone who used this approach with good results is Andreas H?ehne(3rd in WOC 2003) and his Rose-bill and Diagonal.
The second approach also has its strengths and weaknesses. Usually a surprising variation will be technically weaker than the common openings (or else why would it still be a surprise at this point?). But being minus a few discs in the opening means nothing in most human versus human games, with the frequency and size of mistakes humans are capable of. But remember, if you use a variation which is up to -8 in Wzebra (anything worse being almost certain suicide), the response continuation should be hard enough for your opponent to play, that there is a decent chance they will make enough of an error by the time you are also out of book, that it justifies your gamble. And also note that once you play your variation in tournament, your next opponents may check it even on the next break, and perhaps come up with a way to negate your novelty.
Which approach is to be recommended? Depends on the relative strength of you and your opponent. If you feel your mid- and endgame is stronger than theirs, you may want to get him/her out of book earlier to give your skills more time to cement an advantage. And if you are playing a player who is objectively stronger than you are, playing a game with deep book can have the effect of making it difficult for your opponent to create an advantage against you. An example of this used to positive effect, was Ben Seeley’s use of a Rose opening in 2000 to beat Tatsuya Mine, Raphael Schreiber, and Ryan Matreyek, who were all better players at the time- and were his biggest wins that year. Ultimately, your preference for making Othello into a memory exercise, versus an exercise in mental inventiveness, should also be considered.
Choosing and preparing
Remember to choose an opening that suits your preferred style of play. For example, if you don’t like to be on edges, don’t pick an opening which leads you there. Wzebra cannot help you in this situation, because it has no preferred style. You may want to look up the openings other similarly-styled players prefer, to give you a good start (very similar to developing a sense of fashion). Murakami for example, famously good at using the edges to gain an advantage, has used many strong edge-grabbing openings. To find good variations to the openings you are having trouble with, just play it in practice mode and examine the possible variations with Wzebra- both before, during, and after the period that presents the most difficulty.
Once you have downloaded and installed the Wthor database, look at what players normally play against the opening you are planning to play. Wzebra’s Thor tools also give you statistics on how games have ended with each given opening position, for the population of games that fit your criteria, and that have had that position in them. If the variation you are planning to play has ended up with wins for the opposing color in the great majority of games containing it, you should at least learn carefully how to avoid the same result.
If you are a goldmember in the Vog game site, or a member on Kurnik, GGS, or Little Golem, you should use their archive tools, too. The number of games in online databases is huge, and you will find more examples of how humans play the opening you are investigating. Keep in mind that those archives have weaker search abilities, although some have a few features of Thor.
Time to practice
Ok, now you have found an interesting opening and want to practice it. The first thing you should probably do, is learn a few main moves, and then try the opening out on humans. This should help tell you how commonly understood the opening is, and if it is common, what the main lines people know are. If you appear to be surprising everyone, seeing the likely out of book responses will be useful information. With your new information in hand, you can begin to use Wzebra, or the opening tool of your choice.
Try forcing Wzebra to play the opening with no variation. After you have learned to live through the program’s main line, start increasing the opening and midgame variation of Wzebra. Remember that you don’t have to beat the program with your opening, just make sure you won’t mess up on the book or the first few moves after you are out of book. In general, memorizing whole lines to the end is normally a waste of time, because human players almost always go to different lines than your program will, through choice or mistake. Even if your opponent has the same line memorized, one of you may still end up trying to make a gamble for the win.
Another very good way to start with the opening is just play it against yourself in Wzebras practise mode. Figure out what human players most likely will play and then practice your responses.
It is also important to understand why each move is good/bad, rather than just memorize and imitate Wzebra. You should be able to better understand why each move is good or bad, by playing out sequences that arise from each position- we would suggest that you play each sequence of the program’s moves, plus the moves you think are plausible, until you get the ”aha” of why the initial move was considered good or bad. Once you have that, you don’t need any further investigation about that particular move. The nice thing is that you will see a lot of likely lines this way, too.
Now you should be ready to keep practicing and testing your opening against strong humans, and other skill levels comparable to what you will encounter in the tournament. Playing blitzgames is a good and fast way to get lots of feedback about an opening- but keep in mind that in longer games people are likely to come up with something different from the instinctual moves of blitz.
Advanced understanding of an opening
Try to learn the principles and patterns of the openings you practice. In many cases when you go out of book, the position is still quite similar to the lines you already know, and the basic strategy to win with the opening is still the same. Especially if you don’t have the memory capacity or inclination to learn deep lines, it is recommended that you at least get a feel for the key variables in the opening- perhaps a diagonal is critical, or control of an edge. An example- some edge-grabbing openings lead to positions where your goal is to extract critical discs of your opponent, to prevent their access to certain moves later on, and most variations of the opening will require that you use this strategy.
If you are interested in learning strategic principles and patterns, studying openings can be a very easy means of doing so. These principles can then be used to play other openings better. For example, after you have learned to play Rotating flat well, you most likely can play other rotating openings and positions better, too. Some Snake openings are classic exercises in edge-grabbing for Black, and edge-feeding for white- experience that can be used in other situations, in and out of the opening.
For the tournament
If you are planning to play a surprise variation, it is not smart to play it against the players you are most likely to face in the tournament. So practice with strong human players who won’t be in the tournament.
The most dedicated players either make opening plans for each strong opponent they might face in tournament, and/or make an opening set that should work against any response from their opponents. It is not a bad idea to get used to the players by looking at their games in the Thor database, and see what openings they like to play, their style of play, and so on. At least try to figure which part of your opening selection would most likely cover the given player.
But in the end, there are players who literally come up with openings without any practise at all and still get good results. And hey, it’s only a game, who said you have to be so serious about it? =)
Authors: Olli Makkonen & Ben Seeley
[ Last edited by myway on 2006-8-2 at 14:34 ] |
