actually, from what I've seen, the 505T seems to outperform the 920T. I'd reccomend making the 505T your true oil ball, and making the 920T a middle of the road benchmark ball. I'd drill the 505T pin just below the bridge, and the 920T pin above the ring. I haven't actually seen the 718A thrown, but I've heard that it is VERY skid/snap, so i'd probably drill it to give you the option to tame it down. Pin in the ring finger should do it. With polish, it will still be very skid snap, but if you were to put say 2K abralon on it, you could really tame the reaction.