The 2p2h concepts I'll outline in this post are largely paraphrased from what I remember about a post Zombo made back in UPSB V3 era (2007-2010 or earlier). As far as I know, there have only been several short clips or brief applications of these ideas in the past by s777, eriror and tmrw; but not really any complete combos that use varying degrees of synchrony.
Synchrony: happening at same time.
I'm still not sure about what the difference in asynchrony or desynchrony is, so I will be using 'asynchrony' to represent opposite of synchrony (i.e. different things happening).
As inspired by musical theory, there can be varying degrees of discordance (i.e. difference in effect) in what each hand does.
i. The most basic 2p2h is perfect synchrony (no discordance) - where each hand does the same tricks at the same time. This is fairly boring and quite simple, but it can be expanded with transfers like below at 0:27:
ii. Slight discordance - same palm orientation, similar tricks in same slots with slight variation (e.g. doing inverse sonic 34-23 in right hand and sonic 34-23 in left hand). I made a combo with this concept in 10 year solo at 1:31
iii. Moderate discordance - different palm orientation, similar tricks (e.g. doing sonic 34-23 in right hand with palm up, and sonic 34-23 in left hand with palm down). I made a combo with this concept in PSO18 2 hands R1.
iv. Above moderate discordance - different palm orientations, different tricks but with similar changes in motion (e.g. having right hand go from palm down to palm up, and left hand go from palm up to palm down). I made a combo with this concept in 10 year solo at 0:43, tmrw's WC14 qualification combo also applies this.
v. High discordance - different palm orientations, different tricks, different changes in motion and pen spinning in different planes of rotation. This is probably the hardest form of 2p2h (assuming other factors are equal), and most difficult to achieve a cohesive effect with.
In my WT19 R1 combo, 0:01-0:03 has moderate discordance, 0:04-0:07 mainly has slight discordance; 0:08-0:13 has above moderate and high discordance.
It is tempting to consider 2p2h in terms of what each hand does separately, but this is just an initial consideration. Proper depth of 2p2h lies in understanding how the parts fit together.
Besides the consideration of structure, a 2p2h combo is far more difficult than its separate parts. If the breakdown for the right hand part can be done once every 1 minute (1 in 20 success rate) and the left hand part is once every 2 minutes (1 in 40 success rate), then the chance of doing the parts successfully one after the other is 1/20 x 1/40 = 1/800 (once every 2400 seconds = once every 40 minutes). However, it is more difficult to do the breakdowns at the same time, so the difficulty is even higher.
I also put some basic fingercross with left hand at 0:06 and 0:12, but it's just a minor addition to the overall picture.
I have very high respect for Zombo for documenting these theories so long ago, and I thank all pioneers of 2h concepts for giving me inspiration.
Looking forward to seeing people explore 2p2h more in the future! 2p2h does not usually do well in WT, so I hope I can pass to next round.
