Sascha Bajin is a current WTA coach and recently was appointed to work with Yastremska (world #25) earlier this year. Sascha is known for working with multiple WTA players in the last 10 years; coaching Naomi Osaka (2017-2019), Kristina Mladenovic (2019) and being a hitting partner for Serena Williams earlier in her career.
Sascha's biggest achievements in his coaching career so far was working with Naomi Osaka managing to win the 2018 US Open and 2019 Australian Open titles. Winning two consecutive grand slam titles made her the first player to follow up her first title (with a second) since Jennifer Capriati in 2001. Naomi achieved the world number 1 ranking following the Australian Open and had beaten her biggest rivals in the last 12 months; Serena Williams, Simona Halep and Angelique Kerber. Sascha got recognized by the WTA in 2018 and won the 'Coach of the Year' award.
Naomi decided to split with Sascha Bajin after the Australian Open due to 'not wanting sacrifice her own happiness'. Her decision shocked the tennis world and her results went downhill since; now ranked #10 in the world. She has failed to make a quarter-final of a grand slam since this decision and struggled with injuries for a large portion of 2019. Naomi only started to pick her form up again when appointing her father as coach (temporarily) and won two titles during the 2019 Asian swing. Now working with Wim Fessette in 2020, she will look to regain the successes she had with Baijin...
Baijin's biggest strength as a coach was the relationship he had with Naomi during their time together. He seemed to get the best out of her; on court performances, starting to believe in herself and being more positive in her demeanor. In 2018, Naomi said "I tend to be a bit negative on myself - I feel like I've gotten a little bit more optimistic... I fight myself a lot, so he's sort of been, like, the peacemaker."
Naomi has lacked confidence and belief in her own game pre-2017, never ranked inside the top 40. Similar to the best football managers in the world, players have spoken out and said the most important aspect of a 'good manager' was the player/coach relationship (and mentorship), not actually the tactics. It's crucial to have trust and a friendship with your coach, someone who is your friend but also your mentor. Although Sasha didn't seem to make any major technical differences with Osaka's game, the mental, physical and tactical improvement was clear to see.
After reaching the heights of two consecutive grand slam titles, it's probable Sascha wanted Osaka to push on and keep working harder to gain more success. Being world number #1 is harder than any other ranking, everyone wants to beat you and take your position at the top of the world. It would be my understanding that Sascha was very aware of the task ahead, but maybe Naomi wanted happiness over results.
Sascha and Naomi's player/coach relationship was one of the most successful partnerships in recent WTA history. It will be intriguing to find out how Sascha Bajin goes with his new WTA player; Yastrameska, a top 19yr old talent from Ukraine.
Part #2 to come at a later date!