Pakistan have always prided themselves on the quality of their pace attack, but recently that reputation has been under some threat, in ODIs at least. In the three years, between January 2014 and December 2016, Pakistan's fast bowlers collectively averaged 39.57 in ODIs. Among the 19 teams that played ODIs during that period, only four had poorer averages: Zimbabwe (41.29), UAE (42.14), Kenya (44.12), and Canada (45.12).
ODI averages for pace attacks for each team between Jan 2014 and Dec 2016
Team Mat Wkts Ave Econ SR
 Bangladesh  45  180  28.72  5.22  32.9
 Australia  66  409  28.79  5.31  32.4
 South Africa  60  322  28.96  5.38  32.2
 India  60  260  29.37  5.50  32.0
 New Zealand  66  374  31.07  5.65  32.9
 Sri Lanka  76  280  34.39  5.66  36.4
 England  69  333  35.03  5.61  37.4
 West Indies  42  200  35.97  5.98  36.0
 Pakistan  54  194  39.57  5.69  41.6
Then, along came Hasan Ali. Though he had made his ODI debut in 2016, he didn't do too much of note in the eight games he played that year, taking 11 wickets at 31.18, and an economy rate of 5.3 runs per over. They are pretty respectable numbers, but not a patch on what he has achieved this year.
In 2017, Hasan has been the stand-out bowler in ODIs: from just 18 games, he has picked up 45 wickets - easily the highest for the year - at an exceptional average of 17, and a strike rate of 20.3. Along the way, he has also become the joint fourth-fastest, in terms of matches played, to reach 50 ODI wickets, getting there in just 24 games. Only Ajantha Mendis, Ajit Agarkar and Mitchell McClenaghan have reached the landmark in fewer matches. Among Pakistan bowlers, Hasan got there faster than Waqar Younis (27 matches), Saqlain Mushtaq (29) and Shoaib Akhtar (29).
Those numbers have transformed the stats for Pakistan's quick bowlers in 2017. From languishing at the bottom of the table between 2014 and 2016, they have moved to the top in 2017: their average of 25.61 is the best among fast bowlers from the top nine teams this year, while their strike rate of 28.6 balls per wicket is their best in any calendar year.
ODI averages for pace attacks for each team in 2017
Team Mat Wkts Ave Econ SR
 Pakistan  18  98  25.61  5.36  28.6
 South Africa  19  102  29.92  5.20  34.4
 India  25  103  30.71  5.27  34.9
 Australia  15  92  31.32  5.29  35.5
 England  20  107  31.77  5.77  33.0
 New Zealand  16  75  35.41  5.57  38.1
 Bangladesh  14  47  44.72  5.99  44.7
 West Indies  19  61  45.18  5.86  46.1
 Sri Lanka  26  75  48.94  5.85  50.1
Much of the credit for these outstanding numbers should go to Hasan. He has accounted for almost 46% of the total wickets taken by Pakistan's quick bowlers, at an average that is almost half that of the others put together. Without him, the others in the team's pace attack have averaged nearly 33 at a strike rate of 36, numbers that aren't a whole lot better than their stats during the 2014-16 period.
Hasan's strike rate is very Waqar-esque so far, and it's hardly surprising that among Pakistan bowlers who have bowled at least 150 ODI overs in a calendar year, only Waqar has a better average - 12.63 in 1990 - than Hasan in 2017.
The other aspect of his numbers that stand out is the period when he bowls, and is at his most effective. Unlike most other fast bowlers who prefer the new ball, Hasan does most of his work in the middle overs: two-thirds of his overs, and 59% of his wickets, have come between the 11th and 40th overs.
Hasan Ali's ODI stats by phases of an innings
Phase Balls Wkt Ave Econ % Balls
 0.1 to 10.0  174  5  34.2  5.89  13.36
 10.1 to 40  873  33  19.87  4.5  67.05
 40.1 to 50  255  18  15.72  6.65  19.59
Among bowlers who have bowled at least 100 overs in this period against the top nine teams since the start of 2016, Hasan's average is easily the best. In fact, it is 34% better than the second-placed Imran Tahir's average of 25.82, and 68% better than Liam Plunkett, who averages 32.42.
Hasan's wicket-taking ability in the middle overs is perhaps the most impressive aspect of his career so far. While batsmen have become more aggressive during this phase too, the middle overs remains a period where taking wickets is relatively more difficult than in other phases. Not for Hasan, though: he strikes once every 26 balls, while others have struggled to keep that number below 35.
And it is not as if he only contributes during those middle overs. He is pretty handy at the slog as well, averaging 15.72 at an economy rate of 6.65. That's a whole lot better than what his fellow Pakistan fast bowlers, Mohammad Amir, Wahab Riaz or Junaid Khan have managed. Put all those numbers together, and it's clear than Hasan Ali has almost single-handedly revived Pakistan's fast-bowling fortunes in ODIs in 2017.

S Rajesh is stats editor of ESPNcricinfo. @rajeshstats.