Russian oligarch 2004, Putin apparently engaged in a power-struggle with some oligarchs, reaching a "grand bargain" with them. This bargain allowed the oligarchs to maintain their powers, in exchange for their explicit support of – and alignment with – Putin's government. Many more business people have become oligarchs during Putin's time in power, and often due to personal relations with Putin, such as the rector of the institute where Putin obtained a degree in 1996, Vladimir Litvinenko, and Putin's childhood friend and judo-teacher Arkady Rotenberg. However, other analysts argue that the oligarchic structure has remained intact under Putin, with Putin devoting much
Sparring their emotions under control. The level of contact is also debated, lighter contact may lead to less injuries but hard contact may better prepare individuals for competition or self-defense. Some sport styles, such as sanda, taekwondo, tang soo do, Kyokushin kaikan, kūdō, karate, kendo, and mixed martial arts use full contact sparring. Brazilian Jiu Jitsu sparring is full contact and injuries are rare as it does not involve striking but rather forcing the opponent to submit using grappling techniques. There is a lot of controversy in mixed martial arts about the benefits of full contact sparring vs career threatening injuries.