Miami Open 2021: Men's singles forecast and prediction

With Indian Wells having been postponed (or cancelled altogether), the ATP Masters Series for 2021 kicks off with Miami. Sporting a 96-player field as usual, the Miami Open is expected to be the only Masters tournament this year that features seven knockout rounds of competition.

So how does that affect the tournament forecast when compared to, say, five or six rounds of competition? It is pretty elementary.

Let's consider a player who starts out as a forecasted favorite to win a match, simply by being expected to win a greater percentage of service points than his opponent. The way probabilities work, the advantage is expected to magnify the longer the match goes on.

A small difference in probability of winning a service point is magnified a little when it comes to winning a game on serve, which again is magnified when it comes to winning a set, then to winning two sets out of three, and then to winning three sets out of five. Thus, the more the sets, the greater is the chance for the more favored player to win (assuming ideal circumstances, and omitting fatigue and other external factors).

The same concept applies to winning the tournament. A player who starts out as the favorite establishes his advantage further with more matches in the sample space. Thus, the more the rounds of competition, the smaller are the chances of an upset champion on the final day.

With many top players not participating in Miami (including the Big 3), the playing field this year might look more 'open' than usual. But the top four seeds in the draw have distanced themselves from the rest as the primary favorites for the tournament.

Previously used in Dubai, here's the updated Elo table as of 22 March (sourced from Tennis Abstract). In order to generate the tournament forecast, we first calculate the Elo ratings of the players missing in the above linked list. After that, we use the same principle as we did in Dubai to make the match and tournament forecasts.

Elo Ratings for players missing in the original list

Fernando Verdasco is returning to competitive action since last playing in Nur-Sultan 2020

For the players who got direct entry into the main draw and are absent from the aforementioned list, the same formula has been used to estimate their Elo ratings as the one that had been used to calculate Tournament Elo here. In short, their previous matches from 2021 were compared against players whose Elo ratings are already listed.

We have also taken recourse to the following two considerations:

The player whose Elo rating is to be estimated through match/tournament performance, is assumed to be at 1500 Elo at the start of every match being used to thus calculate his Match Elo.
The opponent he has faced is assumed to be at the same Elo rating as he is presently, i.e. on 22 March 2021.
A deduction of 20 Elo points is made for a layoff of each month, exceeding two months from his immediate previous appearance in a competetive match.

We thus arrive at the following Elo ratings for the concerned players:

Sam Querrey: 1,558 (through matches vs McDonald, Mager at Delray Beach; Laaksonen, Travaglia at Great Ocean Road and Sonego at Australian Open.
Yen-Hsun Lu: 1,328 (through matches vs Vukic at Great Ocean Road and Opelka at Australian Open.
Steve Johnson: 1,028 (through match vs Djere at Acapulco).
Jack Draper: 1,131 (through match vs Bonzi at Potchefstroom Challenger).
Fernando Verdasco: 1,581 (through matches vs Duckworth, Millman at Nur-Sultan 2020, with a 60-point deduction for a five-month layoff).

17-year-old Shintaro Mochizuki is entering the main draw of an ATP tournament for the second time

For the players who got entry into the main draw through qualifying we have employed the same formula, using their two completed qualifying matches. And if their calculated Elo has exceeded their formerly recorded best year-end Elo, we have restricted it to the latter.

We thus arrive at the following Elo ratings for the qualifiers:

Thomas Fabbiano: 1,586
Shintaro Mochizuki: 1,412 (also using match vs Celikbelik at Singapore, since one of his qualfying matches wasn't a completed one)
Emilio Nava: 1,691
Mischa Zverev: 1,655
Thanasi Kokkinakis: 1,753

Miami Open 2021 tournament forecast

1st Quarter

Daniil Medvedev, the top seed, is the overwhelming favorite to win the tournament, at a forecasted 36% probability. His dominance on hardcourts of late has been so spectacular, that his chance of winning the tournament is even greater than that of the second favorite to reach the finals (Andrey Rublev, 30.92%).

What stands out in particular is how easily Medvedev is expected to manoeuvre past his early rounds. That in turn would hold him in good stead in the latter stages of the tournament.

But in fact, if anybody were to bet on Daniil Medvedev to lose, they'd rather bet on him losing early than losing late - for he has been nearly invincible when in form. This is further highlighted by the fact that he had a Round 1 exit in Rotterdam following his hot streak of wins, only to bounce back sharply with the title at Marseille.

The favourites from the first quarter to reach the semis are:

(1) Daniil Medvedev: 65.65%
(19) Daniel Evans: 6.28%
(7) Roberto Bautista Agut: 4.98%
(11) Felix Auger-Aliassime: 4.95%

2nd Quarter:

Alexander Zverev enters the Miami Open on the back of a straight-sets win against Stefanos Tsitsipas in the Acapulco final. In fact, Zverev didn't drop a set the whole tournament.

Seeded third, the German goes in as the overwhelming favorite to reach the semis from this section of the draw. He is also the third favorite to win the tournament, at a 12.62% probability.

However, since the forecast doesn't incorporate head-to-head records, it will be interesting to see how Alexander Zverev matches up with the two people ahead of him in the Elo table - Daniil Medvedev and Andrey Rublev - in case they meet. He leads the head-to-head against both the Russians.

The favorites from the second quarter to reach the semis are:

(3) Alexander Zverev: 42.17%
(21) Jannik Sinner: 15.68%
(9) Grigor Dimitrov: 8.91%
(8) David Goffin: 8.00%

3rd Quarter:

Andrey Rublev headlines this section of the draw. While Rublev is seeded fourth, he comes in as the second favorite - though a distant margin behind Daniil Medvedev - with a 16.51% probabilty of winning the tournament.

This might appear as an anomaly given that Rublev hasn't achieved anything big past the ATP 500 level. More specifically, he hasn't ever made it past the quarterfinals of a Masters tournament, and currently has a 14-21 win-loss record in the category.

But a deeper look might reveal a more telling factor.

The bulk of Rublev's Masters appearances have come before his breakout 2020 season, and 2020 hosted only three Masters events. Even though he performed poorly in those three, that is still a very small sample size to base his proficiency on.

That being said, if Andrey Rublev does make it through to the finals, his most probable opponent will be Daniil Medvedev or Alexander Zverev. Rublev hasn't won a single set against either of them, in four meetings each.

The favorites from the third quarter to reach the semis are:

(4) Andrey Rublev: 44.9%
(17) Aslan Karatsev: 12.13%
(5) Diego Schwartzman: 11.25%
(29) Marton Fucsovics: 10.09%

4th Quarter:

Stefanos Tsitsipas, the second seed, is the favorite to emerge from this section. But he enters the tournament only as the fourth favorite, at a 9.9% probability of winning the whole thing.

Like the other top seeds in every other quarter, Tsitsipas is also a firm and clear favorite to make the semis. But he is the least favored to do so among the four.

The Greek has had his own set of deep runs since the resumption of the tour, most notably making the semis of both Roland Garros and Australian Open. But he has failed to capture a title since he last won Marseille in 2020, precisely 13 months ago.

Breaking the drought here would seem unlikely, with three people being favored more than him. But Tsitsipas is still more favored than the 92 other men in the draw.

The favorites from the fourth quarter to reach the semis are:

(2) Stefanos Tsitsipas: 33.21%
(12) Milos Raonic: 15.65%
(15) Alex de Minaur: 13.93%
(6) Denis Shapovalov: 9.11%

Miami Open 2021 semifinals and final forecast

From the top half, the most favored forecasted finalists are:

(1) Daniil Medvedev: 49.68%
(3) Alexander Zverev: 21.02%
(21) Jannik Sinner: 5.82%
(9) Grigor Dimitrov: 2.72%

From the bottom half, the most favored forecasted finalists are:

(4) Andrey Rublev: 30.92%
(2) Stefanos Tsitsipas: 20.18%
(12) Milos Raonic: 7.29%
(15) Alex de Minaur: 5.69%

The most favored forecasted champions for Miami 2021 are:

(1) Daniil Medvedev: 36.00%
(4) Andrey Rublev: 16.51%
(3) Alexander Zverev: 12.62%
(2) Stefanos Tsitsipas: 9.90%
(21) Jannik Sinner: 2.66%
(12) Milos Raonic: 2.59%
(17) Aslan Karatsev: 1.85%
(15) Alex de Minaur: 1.73%