33/33/33

My absence over the weekend isn't to do with Civ VI (as hinted a previous post), but due to attending the 50th birthday party of Charles Zworestine (one of Australia's leading arbiters). Issues with trains late in the evening resulted in a fairly late return to where I was staying (after 1 am) and a missed deadline for yesterdays post.
Despite this I have a quick look at Civ VI and I already think its pretty good. My son mentioned that in updating the game from Civ V (and early versions) the developers used the 33/33/33 rule. Basically, they kept 33% of the game from Civ V as is. They improved 33% of the features in Civ V, and finally, the added 33% new features to the game.
This then got me thinking how this could be applied to chess improvement. Changing how we play is often difficult, but a similar idea might be helpful. If you are thinking of a change of style/opening or approach, then look after you more recent set of games, and see what you are doing right and wrong. Keep 33% of the features where it seems to be working for you, improve the next 33% and finally, replace what isn't working with something that is. By using these ratios, you don't completely throw away everything you know, but at the same time, you do commit to improving existing skills and learning some new ones.
It probably applies best to openings (keep a third, improve a third, change a third), but it may also be applicable to other parts of the game as well.