Sanhok is the third map to be introduced in PUBG. The map has a small size of 4km x 4km, which cause teams to fight earlier and more often. Recently, PUBG Corp. has decided that Sanhok will become an official competitive map starting from Phase 3. The developer thinks that by adding Sanhok to the pool, there will be more diversity and faster game pace as well as more interest matches. However, as of now, there have been several competitive matches played on Sanhok and the results aren't good at all. Here are some of the problem.
As the map is really small, the chance of getting third-partied is really high, so it is actually a bad idea to take fights. Maybe the map is better for Solos and Duos, but not in Squads. Vehicles are also not very helpful in Sanhok as the map is small and most fights happen in close range. Vehicles will create a lot of noise and attract unnecessary attention. Cliffs are also a big problem when they are inside the circle.
Recently, there was a competitive match in Sanhok where 10 players died because of the zone and some teams were forced to jump off a cliff just to get into the circle. Meanwhile, another team was just hiding in the warehouse for 15 minutes doing nothing and win.
According to the pro player Liquid_Ibiza, Sanhok is probably more suitable with 10 Squads per match or the tournament's format need to have some changes. While it seems that from the viewer's perspective, Sanhok might be more interesting than Erangel or Mirarma, the pros don't think so. However, personally, I think that the map just needs some time so the developer can find out the best way to adjust it to fit the competitive setting.