Multiply wave suffering

I have implemented multiply wave surfing, but my local tests shows only +0.17 APS. Then i have search TOP-20 bot's version history to find out another's gains, but there're only 2 bot's has relatively accurate records
Wintermute

0.2: APS:83.19 PL:1366 - 699 pairings

    Added HOT and LT to the weighting schemes (acts as pre-loaded HOT and LT shots)
    Changed the weighting system to give the most accurate scheme all the score, the others 0 (with a rolling average, so it evens out)
    Now surfs the second wave, and differently I believe than to other TrueSurfing algorithms: at each tick along the second wave I check what the danger would be if I decelerated at that point, and then take the minimum danger of all those decelerations, as well as continuing, as the actual danger. Also, the second wave is weighted equally to the first. (This may be changed at a later date.)
    Takes ram damage into account for enemy energy drop 

0.1: APS:82.92 PL:1350 - 698 pairings 

Garm

V. 0.6i: rank: 33 PL-rank: 24 rating: 1944.58 date: 04.01.2007

    fixed movement bug (introduced in V. 0.6f)
    now surfs the first two waves
    moves some degrees away form the enemy instead of staying perpendicular 

V. 0.6h: rank: 47 PL-rank: 37 rating: 1891.7 date: 24.12.2006

So question is "Is +0.17 APS gain corresponds to multiply WS or there're still bugs or room for improvements in my implementation"?

For GresSuffurd this was a long time ago, but it has reasonable reliable stats between 0.1.8 and 0.2.1. Difference is 18 ELO-points which is almost 1 full APS-point. Note that at that time the only surfingattribute was lateral velocity, and no-one had heard from precise prediction.

0.2.1 (20070117) member of The2000Club 
gun: GV 0.2.2 move: WS 0.1.5 
Rating: 2000 (21nd), PL: 448-40 (37th) 
bugfix weighting of waves 
0.2.0 (20070114) 
gun: GV 0.2.2 move: WS 0.1.4 
Rating: 1992 (22nd), PL: 444-43 (38th) 
removed nearwall segmentation 
also evaluate second wave 
0.1.9 (20070102) 
gun: GV 0.2.2 move: WS 0.1.3 
Rating: 1980 (23nd), PL: 439-43 (40th) 
segment movement also on nearwall (3 segments) 
0.1.8 (20061212) 
gun: GV 0.2.2 move: WS 0.1.2
Rating: 1982 (22nd), PL: 436-44 (41st)  

Chalk also gained a lot of points in v2.5 (oldwiki:Chalk/VersionHistory) - I think about 50 ELO points, based on some chatter on Chalk/Archived Talk. There were multiple changes, but he attributed it mostly to changing his multiple wave surfing from a very basic approach to more like what I do in my bots.

This has come up a few times lately, so maybe I should release a one-wave version of Diamond or Dookious to the rumble and see where it ends up...

I think I only gained maybe a quarter APS point from my multi-wave surfing. I'm planning on going back and working on it more in the future sometime -- first, to just verify what difference it currently makes, and then to see if I can improve it. I'm also curious how much of a difference multi-wave surfing makes in true surfing vs go-to surfing. My drive is of the go-to variety, though it may change it's mind once or twice per wave depending on the changing battlefield conditions.

I think that using bullet shadows is the cause that second wave evaluation has less impact than it used to have. The infuence of bullet shadows is that big that second wave differences are just marginal.

Thanks for all for response