Easy and hard layouts in Mahjonng Titans

You can download Mahjonng Titans here, although it comes free with many Windows installations. I've played the solitaire-like game since mid-2010, with about a 50-50 win/loss average.
See my win percentages for the different layouts*:
Turtle         28 / 80       35%          
Dragon      13 / 24       54%          
 Cat           13 / 20       65%          
Fortress     13 / 24       54%         
Crab          13 / 22       59%         
Spider        14 / 30      46%         
Table: Percentage of games played that I won (All Layouts || 94/200 || 47%)  

It seems that Cat is particularly easy, and one may suppose Crab is the 2nd easiest.  I win nearly 2/3 of these games.
It seems that I find Turtle hard, winning about 1/3 only, and that I have also played it A LOT compared to the other configurations: while I played Turtle 80 times, I only played each of the other layouts 20 to 30 times. 

Crab is easy

From the winning percentages column, I can deduce this order of easiest to hardest layouts:
Cat - Crab - Dragon/Fortress (tied) - Spider - Turtle

In other news, the layouts I have played the most have the lowest percentages.  Plot total games played against win percentage and you see this.  But what does this mean?  Does this mean that I play the harder ones more - I love a challenge?  Or maybe my game gets worse as I play along?  

Negative correlation between win percentage and number of games played

How about you, which layouts do you find easy/hard?

I actually feel like the truly easy ones are Cat, Crab, and (surprise) Turtle.
I think that Dragon and Fortress and Spider are tricky, but that once I found the trick, I started playing these three layouts better while at the same becoming worse in Turtle.  Could my added knowledge actually have worsened my game in Turtle?  Does this seem ridiculous to you?

* I have given my real playing data for this software installation.  I did not plan to have the round numbers (80 games of Turtle, 200 games in total, 13 games won in each of four layouts...)  These are coincidental, believe it or not.

It is now NOVEMBER 2011 at this monthly blog.