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Monday, 3 March 2014

Chess: Ruy Lopez Exchange Variation

Some games are classics.  Some are so disastrously filled with blunders that the only way you're going to win is by committing fewer blunders and, ideally, not be the last person to commit one.

This is one of those games.  It started off well enough, with the Ruy Lopez Exchange Variation (I knew a few moves, which got me started), but then the game descended into a number of unusual moves.  Or blunders.  And I missed at least one key opportunity to secure a big win... again.

Here goes.

Dave Johnson vs David Leese, Kidsgrove Chess Club, Roy Bennett Cup. 25 Feb 2014

1. e4  e5
2. Nf3  Nc6
3.  Bb4 a6
4. Bxc6 dxc6 


So far, soo good.  All by-the-book.  I've had to recapture with my d-pawn (away from the centre) to ensure I don't lose the e-pawn (I can meet Nxe5 with Qd4, forking pawn and knight and subsequently regaining the pawn).

5. d3 Bd6    (White plays to protect his e-pawn, so the threat of Nxe5 is back on.  I protect my e-pawn with my bishop, which seems okay to me.)
6. O-O Bg4 
7. d4 exd4 (White's move surprised me.  What's he doing, moving a pawn twice during development?  I've pinned his knight on f3, so I am eyeing up the possibility of doubling his f- and g-pawns with an exchange).
8. Qxd4 Bxf3 (... so far, so good, it seems, all going according to my plan).
9. Qxg7 Qh4 (I missed Qxg7.  But I've decided I'm not playing cautiously, and if I can't save my rook, I'm going to get some counterplay out of it.  Here, I'm threatening Qxh2#, and I've decided that this game is not going to be a draw).

At this stage, I'm thinking of various threats, apart from Qxh2#.  I'm anticipating various defences, including 10. h3, where I'll then play Bxg2 and possibly Qxe4.  I really need to think ahead (I was playing on adrenaline, which is never a good idea) and I didn't see White's defence (which was also a mistake). 

10. e5? Be2? 

An error from White, followed by a massive, massive mistake by me.  After 10. e5, the best answer was Bf8, threatening all kinds of nastiness.  Here's the position after 10. ... Bf8, the best move for Black.

Note that Black is currently a piece up (White has not recaptured on f3, as he hasn't had time and opted to capture on g7 instead).  And his Queen is attacked, so he can't recapture on f3 just yet either.  I wish I'd seen this move at the time - I was too busy working out how to save my pieces, and this was the obvious answer:  if I can't threaten the King, then chase the Queen.  Here, White can't capture the rook, because Qxg8 falls to ... Qg4, and after g3, Qh3 has no reply.  White's only answer here is Qg5, and after an exchange of queens and Black's Bd5 or Be4, Black is a piece up for a pawn (although his pawn structure is a mess).

But no, I played Be2.  I moved my bishop away from its prime location in front of White's king, and attacked the rook instead... it's become a desperado.  In fact, both bishops have ... what am I thinking?
11. exd6 Bxf1 
 12. Qxh8 O-O-O
  

I have a plan here, working around Kxf1, Qc4+, and then either Re8+ or Qxc2 with various threats.  However, White isn't bothered with the Bishop at the moment.  I should probably have played Qg4 to press the issue (threatening Qxg2#) and force the capture.  Did I see this?  No.

13. Qe5 Rxd6  (here comes the rook...)
14. Nc3 Rf6?  (White plays Nc3, developing the knight and denying my rook the d1 square.  I decide, after some thought, to threaten checkmate - the threat is Qxf2 and the Qxg2#).
15. Qe8#

If there's only one thing quicker than 'checkmate next move', it's 'checkmate this move'.  I have got my king into trouble, and then disconnected the queen and the rook from the back rank.

All in all, I would have to categorise this as a series of missed opportunities, finished off with a disastrous mistake, and all because I got rattled by the Qxg7 move (which could have paved the way for me to win).  If I think clearly, and avoid panicking, I can probably be a much better player.

Here are some of my Ruy Lopez games (seems everybody wants to play this if they aren't going to use the Patzer), and a stray Sicilian.

Ruy Lopez with 2 ... f6
Ruy Lopez game with 3 ... Nf6 4 O-O
Ruy Lopez Exchange Variation
Sicilian, Smith Morra Gambit

Multi Variate Testing - Online Panacea?

I've discussed multi variate testing previously - outlining the theory, the ideas, the maths and ways in which it can be done.  But, in my discussions with other web analytics and optimisation professionals, it seems that MVT isn't really being used all that widely.  This surprised me at first - after all, the number of tools vendors and suppliers who offer MVT is growing all the time, and I assumed from their sales material that it was the next level of A/B testing and the future of online optimisation.  Additionally, it's often marketed as an online panacea, that will highlight the way forwards for your ecommerce business, and bring in double-digit growth (in whichever metric you'd care to measure).

However, out of a dozen or so online professionals that I've spoken to in EMEA, only one had tried it, and had obtained mixed results.  So, why isn't it being taken up and used as widely as I'd expected?  Here are some possibilities:

1.  It's difficult to code
2.  It's difficult to identify MVT opportunities
3.  It's quicker to do an A/B test
4.  It's difficult to explain to the Boss

Let's look at take a look at a simple example of MVT, which will hopefully address the first two challenges that online optimisation professionals face.  I say 'simple', but it's easier than most test ideas because it concerns making some straightforward changes to a web page:  taking things away.

Our content pages; our product pages; our shopping and ecommerce pages are all full of the most important content we can produce for our visitors - glossy images; descriptive text; eye-catching call-to-action buttons; all working together to produce the perfect digital shopping experience.  Or perhaps they aren't.  Perhaps it's a huge mish-mash of competing elements, some of which are helping, and some of which are distracting users and putting them off.  So:  what's working, and what isn't?

Let's take an example from maplin.co.uk  - they sell a wide range of electronics and electrical items.  I've selected one at random, a keyring torch.  I've highlighted below various parts of the page which could be removed as part of a test (I should probably say at this point that this test will require access to the global template for product description pages - if this isn't going to work for you, read ahead to another example). 

Click on the image to see a larger version.


 The product page is very similar to many other ecommerce pages (similar layouts are used on various sites to sell clothes, furniture, games, toys... you name it).  But what's the value of each component, and how do they work together?  I've covered interactions between elements in MVT previously.  The easiest way of working out the optimum combination of elements is to selectively remove them in a multi-variate test.

Here's the recipe definition for each of the various combinations that are possible:


Recipe Reviews Social Tabs Banner
A Yes Yes Yes Yes
B Yes Yes Yes No
C Yes Yes No Yes
D Yes Yes No No
E Yes No Yes Yes
F Yes No Yes No
G Yes No No Yes
H Yes No No No
I No Yes Yes Yes
J No Yes Yes No
K No Yes No Yes
L No Yes No No
M No No Yes Yes
N No No Yes No
O No No No Yes
P No No No No

Note that Recipe A is the control state (with all elements present) and Recipe P is removing everything; there are then the various combinations of the four elements in between the two.  (If you're feeling mathematical, you can review how the patterns for each of the four elements changes in a binary-type way - 1000, 1001, 1010, etc. and how the table has certain symmetries).  The number of recipes can be calculated by the number of options for each element (yes or no means 2 options), raised to the power of the number of elements (four elements) so 24= 2 x 2 x 2 x 2 = 16 recipes.


So:  sixteen recipes like this is simply not realistic for a normal A/B/C/D/n test.  The traffic requirements are far too high, and you'd probably be waiting six months for results.  However, because the elements are independent (you don't have to have the reviews included to have the social bar), we can carry out a multivariate test which has only a sample of these recipes, selected to ensure even coverage of the four elements, and which will (with the appropriate tools) enable you to work out the optimal combination, even if you didn't test it.
This example was on a product information page, and as I mentioned above, if you want to test here, your coders will need access to the global template file so that you can run the test across all product information pages.  There are, however, single-page options that would work just as well:
- landing pages for online/offline marketing campaigns
- your home page
- checkout pages

In these cases, each page is (typically) built for a specific purpose and with specific content, so you have much more flexibility on what you can test.  For example, should you have a "Chat online" option and a telephone number on your landing page, as well as an option for online feedback?  Are all three really needed?

This testing has some key advantages: 

1.  You can test a large number of element changes on the page in one go

2.  You can understand (with accurate analysis) the contribution each element makes to page performance
3.  There's no new content required from the design or marketing teams - you're only handling existing content - so no reliance on them for images or content.
4.  It's usually easier to remove page elements with code than it is to insert them, so your code developers will be happier
5.  It's relatively easy to explain what you've tested to the Boss.
6.  In this case, it's definitely quicker than A/B testing, and the more elements you choose to test, the larger the advantage becomes. 

It also has some key requirements:

A.  You're going to need to be able to interpret the results.  This will require some careful analysis and understanding of the maths behind multi-variate testing, in order to work out what each element is contributing (in a positive or negative way).  Many of the tools that are available (here's a list of some of them) offer and promise this kind of analysis, but I'm not aware of it being widely used, so it may be prudent to discuss your requirements with your account manager (I don't work for a tool provider).  You don't really want to get to the end of a test and discover that you have spent eight weeks collectin a mountain of data that you can't climb... that would really require some explaining to the boss.


B.  You're going to need more traffic than a typical A/B test, even if you're using a mathemetical method (such as the Taguchi method) to reduce the recipe requirements, so be prepared to wait longer than usual for your results.


I hope in this blog post I've been able to encourage you to think about using MVT, and shown you how to overcome some of the initial hurdles to getting an MVT idea together - and hopefully into execution.  Please do let me know (either in the comments, or by contacting me) how your efforts go!

Here's my series on Multi Variate Testing

Preview of Multi Variate testing
Web Analytics: Multi Variate testing 
Explaining complex interactions between variables in multi-variate testing
Is Multi Variate Testing an Online Panacea - or is it just very good?
Is Multi Variate Testing Really That Good - (that's this article)
Hands on:  How to set up a multi-variate test
And then: Three Factor Multi Variate Testing - three areas of content, three options for each!