Tyrogue Evolution MethodBesides eevee and clamperl, tyrogue is the only Pokemon in GO that has multiple evolutions. In the Mainstream Pokemon Games, Tyrogue's evolution is based upon its Attack and Defense Statistics at Level 20: if Tyrogue has a higher Attack Stat than Defense, it evolves into Hitmonlee; if its Defense is higher than its Attack, it evolves into Hitmonchan; and if it has equal Attack and Defense, it evolves into Hitmontop. Unfortunately, these parameters don't exist in Pokemon GO. Instead, there is another method in order to get a specific evolution of Tyrogue.
Much like its evolution method in the Mainstream Games, tyrogue's Evolution in Pokemon GO is based on its stats. But instead of a comparison to its Attack and Defense Stats, Tyrogue's Evolution is based on its best stat given during an Individual Value Appraisal from your Team's Leader. If Tyrogue's HP Stat is its best stat, it will evolve into Hitmontop; if its Attack Stat is its best stat, it will evolve into Hitmonlee; and if its Defense Stats is its best Stat, it will evolve into Hitmonchan. However, if Tyrogue has two or more stats that have equal IVs, its evolution, like Eevee's outside of the nickname trick, will be at random.