Oh brother you guys are so off track...first of all thats the strategy you thought of but obviously shika is a master strategist he will come up with a counter strategy for that and second just because he's not on the ground doesnt mean shadows can't reach him you do realize that right? shika can use any shadow as long as he can connect his with it so that would leave a world of possibilities for shikamaru to come up with something. Shikamaru would win no problem, although thats just based on what we've seen of sai's power so far I mean we haven't seen his true power yet after all.I'd say Sai, cause he can fly with his paint animals making Shika's shadows useless. Sai would only need to send animals from a distance to wear Shikamaru out, and then strike when hes all out of chakra and stamina. If then he gets caught, it shouldn't be too hard to break free.