This actually seems like an interesting idea to work with
My belief
#1 WubWoofWolf (Incredibly active and a ton of DT PP that he has yet to get
Shotgun Senorita, Hoshizora no Ima, Remote Control, Gangsta (wishful thinking), etc.)
#2 hvick225 (Haven't seen much from him, but stuff like Shotgun Senorita HDDT 99% lead me to believe he can keep his #2 rank with ease)
#3 HDHR (Don't know much about him, but he seemed to reach his current rank (#4 as of 11/03/2015) out of nowhere. If he keeps it up, he should be able to reach this rank)
#4 Rafis (Seem some pretty crazy stuff from him. Don't know about his activity, but I feel it's reasonable to believe he can reach this rank)
#5 isokasapupuja (Impressive DT scores like The Island, and he also (to me) seemed to come out of nowhere)
#6 _index (Impressive HR scores from him, like Yooh - Salvation and Yooh - snow storm -euphoria-. If he gets scores that good with HD as well, then that seals the deal)
#7 Azer (Him and HappyStick's competition with each other have brought their ranks up a lot. He's jumped 29 ranks in 2 months, I mean, c'mon. With the circle size PP boost, his HDHR skill is going to help)
#8 HappyStick (Unfortunately, usually behind Azer in ranking, but his plays are impressive, and both his HR and HDDT skill will help him get up to this rank)
#9 rrtyui (He's just having fun playing the game. I don't think he'll drop right off the top 10 list since when he gets a good score it's typically high PP as well, but he's not a PP farmer and I don't expect him to become one)
#10 Angelsim or Tokichii (I'm torn between the two. Angelsim is an incredibly impressive mouse player in HDDT, and I've also seen impressive stuff in HDHR (you know what I'm talking about). On the other hand, some of Tokichii's DT plays are crazy, including his Gangsta 1xmiss that I saw on Reddit)
Unfortunately, with his military work, Sayo is inevitably going to fall off the top 10. I also wanted to mention a few players, either because I didn't put them up for lack of knowledge of them, or unpredictability. These players are kuu01, Dsan, thelewa, CookieNia and Kynan. With kuu01 and Dsan, they hold high ranks on the leaderboard currently (#11 and #12 respectively, 3/11/2015), but I don't know enough about their skill level and activity to put them on my list with confidence. With thelewa, CookieNia and Kynan, I can't really predict them well. thelewa has his RSI problem, but he's still stayed in the top 10 since forever. If his problem clears up, then he would probably hold a spot in the top (kicking Angelsim and Tokichii of the list
). Kynan and CookieNia are in similar boats. They're undoubtedly two of the fastest, if not the fastest, players in the game. This could mean some incredible DT plays from them, which could help them climb the leaderboards very quickly. Kynan's probably the hardest to predict, because if he can nail his aim, he could get back up to the top ranks very fast.
tl;dr
#1 WubWoofWolf
#2 hvick225
#3 HDHR
#4 Rafis
#5 isokasapupuja
#6 _index
#7 Azer
#8 HappyStick
#9 rrtyui
#10 Angelsim/Tokichii
Special mention to kuu01 and Dsan, and Kynan, CookieNia and thelewa for not enough knowledge to place them confidently and unpredictability respectively.
I got too into this ;-;