Maria Sharapova sits down with Darren Rovell to talk about why she started taking meldonium and why she doesn't believe it is a performance enhancing drug. (1:03)

While Maria Sharapova's drug suspension wasn't reduced as much as she would have liked in the Court for Arbitration of Sport appeal ruling that was issued Tuesday, CAS' decision to cut her ban was a qualified win for the tennis star, her legacy and her hopes of adding to her total of five Grand Slam victories before she retires.

That said, the decision to reduce her suspension from the two years she was originally given by the International Tennis Federation to 15 months because she was not "an intentional doper" should still provoke some soul-searching in tennis on a bigger scale. Like the recent ban of two officials for electronically relaying information to bettors during live matches -- and a poll earlier this summer showing that 22.5 percent of 31 players polled believe they know a fellow player who uses performance-enhancing drugs -- Sharapova's positive test will do little to disabuse critics of the notion that there is more going on behind the curtain in tennis than anyone -- especially tennis -- would like to admit.

The sport has tried to make better efforts to police itself against banned substances and match-fixing and the like; but as this ESPN investigative report Monday also showed, the sport's drug-testing efforts are woefully below state-of-the-art and unlikely to catch people who dabble in stronger illegal aids than the 29-year-old Sharapova took. Even when the ITF does catch someone, it has trouble making its disciplinary rulings stick before CAS, a court of last resort for the world's athletes.

Sharapova pounced on the opportunity to note that Tuesday. In a statement posted on her Facebook page, she said: "I have learned from this, and I hope the ITF has as well. CAS concluded that 'the Panel has determined it does not agree with many of the conclusions of the [ITF] Tribunal ...'"

Sharapova added: "I've gone from one of the toughest days of my career last March when I learned about my suspension to now, one of my happiest days, as I found out I can return to tennis in April. In so many ways, I feel like something I love was taken away from me and it will feel really good to have it back."

Sharapova was the top-ranked woman on Forbes' list of the world's highest-earning athletes in 2015 at No. 26 overall. She has fallen to No. 88 in 2016 since her suspension was announced.

She had asked CAS to reinstate her immediately, hoping to limit her suspension to the nine months she has already served since first testing positive for meldonium in January at this year's Australian Open rather than serve the two-year suspension she was given by an ITF Tribunal in June.

While that didn't happen, Sharapova can now justifiably point to how she took responsibility up front at a news conference in March and served her punishment for making a costly mistake -- but was cleared of any nefarious motives beyond that by two different governing bodies: first, the International Tennis Federation (ITF), and now the CAS. She remains suspended because both panels did find fault with aspects of her behavior, such as not listing her use of meldonium on doping control forms and not applying for a therapeutic use exemption.

That's a win.

CAS agreed in principle with the ITF's June ruling that Sharapova had taken meldonium -- which is also known by its brand name Mildronate -- to enhance her performance. But the panel did not believe she intended to cheat.

That distinction is important.

Worldwide and national doping agencies generally take the hard-line position that whatever goes into an athlete's body is ultimately the athlete's responsibility -- period, end of story; but teasing out intent is important to authorities like CAS when it comes to sentencing.

In Sharapova's case, both CAS and ITF accepted her insistence that she had been taking meldonium since the age of 17 for therapeutic reasons on the advice of a doctor back in her native Russia, and that neither she nor her camp were aware it had moved to the banned list on Jan. 1 of this year.

There was also no doubt Sharapova hoped meldonium would help her play better tennis. The ITF's 33-page decision cited old emails from Dr. Anatoly Skalny, the Russian doctor who treated Sharapova from 2004-12. He advised her to increase her dosage during "games of special importance" to 3-4 pills one hour before her matches. Sharapova listened. The ITF report said Sharapova used Mildronate six times in seven days at Wimbledon in 2015 -- and five times in seven days at the Australian Open.

If Sharapova had been found to have deliberately violated anti-doping rules, she could have received the maximum four-year ban.

Had CAS even upheld the ITF's original two-year suspension, she would have been 30 by the time she was eligible to return on Jan. 26, 2018 and missed seven Grand Slam events in addition to this year's Rio Olympics, which she had hoped to play in for Russia.

Instead, she now joins Richard Gasquet, Dimitar Kutrovsky, Marin Cilic, Viktor Troicki and, most recently, Varvara Lepchenko as tennis players whose drug suspensions have been reduced because of various extenuating circumstances.

Tennis is also still dealing with the specter of Rafael Nadal suing a French official who publicly insisted that the Spanish star, long the target of PED rumors, benefited from one of the "secret bans" that tennis allegedly gives stars who test positive. That case raises echoes of how Andre Agassi revealed in his post-retirement autobiography that he failed a test in 1997 after taking crystal meth, then lied to ATP tennis authorities to escape punishment -- and the ATP believed him. The failed test remained a secret his entire playing career.

Sharapova seems understandably eager to get on with her career.

In recent days, she had been posting photos and video on Twitter of herself training on the court and in the gym. It might actually help that she's had experience coming back from long layoffs before due to injuries.

Some people who read the full CAS or ITF reports or pay close attention to the worldwide anti-doping fight might continue to be skeptical that someone as famously detail-oriented and ambitious as Sharapova could've made such a lazy mistake as not checking the new additions to the 2016 banned substance list.

Sharapova is likely to experience little fallout going forward unless she stumbles again. The June ITF ruling alone was enough for Nike, one of Sharapova's many top-shelf sponsors along with Porsche, Evian, and Tag Heuer, to resume its endorsement deal with her. Others are likely to follow.

Now that CAS has ruled, Sharapova's public image isn't likely to suffer much going forward.

Sports fans, in particular, have long been a forgiving lot, especially if people they already find likeable are willing to apologize for their mistakes.

Sharapova is probably never going to totally change the mind of cynics who continue to question her story, and how her use of meldonium dovetails with the systemic doping that led to the ban of many Russian athletes from the Rio Olympics and Paralympic Games. Even on a common-sense level, there are snags. As one skeptic wryly noted during the French Open, "Why would Sharapova start a candy company if she was really taking meldonium because of her family's history of diabetes, as she said she was? Does someone afraid of diabetes do that?"

Sharapova doesn't have to acknowledge those questions anymore.

She's cleared of being "an intentional doper." That will be enough.