We also tried the transformations of the power family on the dependent variable Y using the Box-Cox method [11]. A lambda value other than 1 improves the  to about 90%. The three features mentioned above again show significance in the model. But some other features – the fraction of null sequences and density particularly – which are skipped in the first model show impact here. This confirms that the three features are likely important for affecting the performance, but we can't rule out other features.