Research · Indian Premier League
IPL Dew and Chasing: The Advantage Everyone Assumes Is Not in the Data
Every completed IPL match since 2008, matched to the hourly evening dew-point gap and humidity rise at its own ground, then measured against both its season and that ground's own baseline. The chasing team does not win more often when the air is at its most humid, and second-innings scoring does not rise. This is a published null.
Headline numbers
Matches analysed
1,195
2008–2026, 37 grounds
Completed 20-over matches with a result. Rain-shortened and super-over matches excluded.
Heaviest dew band
+2.6 pts
t = 0.47 on 93 matches
Chase win rate against dry-air matches, adjusted for season and ground.
Second-innings runs
+4.6 runs
t = 1.32 in the heaviest dew band
Also a null. No band clears the noise boundary.
Across the sample the side batting first averages 169.3 runs and the side chasing 156.4; the chasing team wins 54.4% of matches while the toss winner wins only 51.5%, despite captains electing to field first 66.4% of the time.
Dew-point gap, band by band
The dew-point gap is the distance between air temperature and dew point during the second innings. As it closes towards zero the air approaches saturation and dew settles readily; a wide gap means dry air and no dew. Each match is compared with the dry-air control after removing both its season's average and its own ground's average — so a humid coastal ground is never being measured against a dry inland one.
| Second-innings dew-point gap | Matches | Chase win rate | vs control | t | 2nd-inns runs | vs control | t |
|---|---|---|---|---|---|---|---|
| Heavy dew signal (under 2°C gap)avg 1.37°C | 93 | 51.6% | +2.6 pts | 0.47 | 154.6 | +4.6 | 1.32 |
| Moderate (2–4°C gap)avg 2.94°C | 314 | 48.1% | -1.3 pts | -0.37 | 155.0 | +2.6 | 1.22 |
| Light (4–7°C gap)avg 5.21°C | 217 | 60.8% | +7.1 pts | 1.84 | 153.4 | +2.1 | 0.92 |
| Dry air (7°C+ gap)avg 15.86°Ccontrol band | 571 | 55.9% | baseline | baseline | 158.5 | baseline | baseline |
Roughly |t| ≥ 2 is our noise boundary. Nothing on this table reaches it. The heaviest dew band moves the chase win rate by +2.6 pts (t = 0.47) and second-innings scoring by +4.6 runs (t = 1.32). The largest chase-rate figure on the page belongs to the middle light-dew band at t = 1.84 — under the boundary, in a band with drier bands on one side and wetter on the other, which is the signature of noise rather than a dose-response effect.
Humidity rise between innings
A second, independent proxy: how far relative humidity climbed between the first and second innings. If dew settling mid-match were driving results, nights where the air moistened sharply should behave differently from nights where it dried out.
| Humidity change, 1st to 2nd innings | Matches | Chase win rate | vs control | t | 2nd-inns runs | vs control | t |
|---|---|---|---|---|---|---|---|
| Large rise (10%+)avg 13.15% | 185 | 57.8% | +7.9 pts | 1.16 | 155.2 | +1.2 | 0.29 |
| Moderate rise (5–10%)avg 6.67% | 465 | 54.2% | +3.7 pts | 0.59 | 156.6 | +2.3 | 0.62 |
| Small rise (0–5%)avg 2.43% | 475 | 54.3% | +4.6 pts | 0.74 | 156.3 | +2.0 | 0.52 |
| Drying air (falling)avg -4.19%control band | 70 | 47.1% | baseline | baseline | 158.1 | baseline | baseline |
The same answer from a different angle. The largest humidity rise band moves the chase rate +7.9 pts (t = 1.16) and second-innings scoring +1.2 runs (t = 0.29). Every band here clears our 40-match minimum, including the 70-match drying-air control, so the nulls are not a sample-size artefact.
Ground by ground
Chasing records differ sharply by ground — and the pattern does not follow humidity. The most reliably humid grounds in the competition sit in the middle of the chasing table, while the driest air in the sample belongs to the ground with the strongest chasing record of all.
| Ground | Matches | Chase win rate | Avg dew-point gap | 2nd-inns runs |
|---|---|---|---|---|
| Wankhede Stadium, Mumbai | 130 | 54.6% | 3.76°C | 162.2 |
| Eden Gardens, Kolkata | 101 | 55.5% | 2.85°C | 159.2 |
| Arun Jaitley Stadium, Delhi | 98 | 53.1% | 15.99°C | 159.8 |
| M Chinnaswamy Stadium, Bengaluru | 97 | 55.7% | 9.48°C | 162.1 |
| MA Chidambaram Stadium, Chennai | 96 | 46.9% | 3.35°C | 152.4 |
| Rajiv Gandhi International Stadium, Hyderabad | 86 | 53.5% | 14.36°C | 158.5 |
| Sawai Mansingh Stadium, Jaipur | 67 | 65.7% | 21.56°C | 157.3 |
| Punjab Cricket Association Stadium, Mohali | 60 | 56.7% | 14.71°C | 157.6 |
| Maharashtra Cricket Association Stadium, Pune | 51 | 45.1% | 5.32°C | 144.4 |
| Dubai International Cricket Stadium | 43 | 51.2% | 7.52°C | 147.1 |
| Narendra Modi Stadium, Ahmedabad | 40 | 50.0% | 18.60°C | 166.0 |
Only grounds with at least 40 matches are listed. This table is descriptive: ground-level chasing records mix pitch character, squad quality over the years and sample size, and none of it is offered as a weather finding.
Season by season
| Season | Matches | Chase win rate | 2nd-inns runs | Avg dew-point gap |
|---|---|---|---|---|
| 2008 | 56 | 60.7% | 150.9 | 11.59°C |
| 2009 | 53 | 52.8% | 137.6 | 4.37°C |
| 2010 | 59 | 47.5% | 149.8 | 11.26°C |
| 2011 | 69 | 53.6% | 141.0 | 9.03°C |
| 2012 | 74 | 54.0% | 145.9 | 9.66°C |
| 2013 | 74 | 50.0% | 140.7 | 10.41°C |
| 2014 | 58 | 62.1% | 153.9 | 9.10°C |
| 2015 | 54 | 42.6% | 150.9 | 6.77°C |
| 2016 | 56 | 67.9% | 156.3 | 10.04°C |
| 2017 | 57 | 54.4% | 154.2 | 10.82°C |
| 2018 | 57 | 54.4% | 161.8 | 9.69°C |
| 2019 | 57 | 61.4% | 158.0 | 10.63°C |
| 2020 | 56 | 51.8% | 151.5 | 7.04°C |
| 2021 | 59 | 62.7% | 150.9 | 7.67°C |
| 2022 | 74 | 50.0% | 158.5 | 4.18°C |
| 2023 | 71 | 45.1% | 166.9 | 9.41°C |
| 2024 | 71 | 50.7% | 176.2 | 12.44°C |
| 2025 | 69 | 52.2% | 176.6 | 12.32°C |
| 2026 | 71 | 63.4% | 180.4 | 11.25°C |
Scoring has risen substantially across the competition's history and chase win rates swing widely from season to season on 60-odd matches apiece. That is why every band comparison removes the season average before anything is compared.
What actually holds up
- Dew does not decide chases. The heaviest dew band is +2.6 pts on the chase rate, t = 0.47. Nothing here supports the routine claim that batting second is materially easier on a dewy night.
- Dew does not add runs. Second-innings scoring is flat across every dew and humidity band once season and ground are removed.
- The general chasing edge is real but small. 54.4% against a 51.5% toss-win rate — and it is not a weather effect.
- Two proxies, same answer. The dew-point gap and the humidity rise are measured independently and both come back null, which is stronger evidence than either alone.
- No coefficient. This study adds nothing to our live model. A null result that we publish is a coefficient we refuse to invent.
Method and limits
- Sample: 1,195 completed 20-over IPL matches with a result, 2008–2026, across 37 grounds, each matched to hourly archive weather at the ground's own coordinates.
- Exclusions: 48 matches in total — 23 rain-shortened (dls applied); 25 no result or decided by super over.
- Every figure is adjusted for both season and ground. Each match is measured against its own season's average and its own ground's average before bands are compared, so neither era drift nor the natural humidity of a host city can carry a result. On the raw unadjusted cut the humid bands look worse for chasing, purely because the humid grounds are the lower-scoring ones.
- Minimum sample is 40 matches per band, a threshold already in use across our earlier studies and set before this study was run. Every band on both tables clears it, and any band that did not would be labelled in the table itself.
- Dew is measured by proxy, not observed. The dew-point gap and the between-innings humidity rise both indicate conditions favourable to dew; neither confirms moisture on the outfield. A real effect confined to nights where dew genuinely settled could be diluted here.
- Start times are not recorded in the match archive, so innings windows are fixed at 20:00 and 22:00 local, matching the standard evening start. Afternoon matches are misread and add noise.
- No market claim. We hold no archive of closing IPL odds or totals, so nothing here says whether a dew effect is priced.
- This is a null result, published as one. It does not prove dew never matters in cricket — it shows that across nineteen IPL seasons, using two independent moisture proxies, no dew effect on chasing or second-innings scoring rises above noise.
References & data sources
- Open-Meteo ERA5 historical reanalysis — archive-api.open-meteo.com (hourly game-window weather at each venue’s own coordinates)
- Cricsheet ball-by-ball match archive — cricsheet.org/matches (IPL match results, toss decisions, innings totals and ground names)
- OverUnderWeather IPL match archive — 1,243 matches parsed from ball-by-ball data, 2008–2026, matched to ground coordinates and evening weather.
- Every dated change we have made to a published study is listed on our corrections log.
Last recalculated
Figures on this page are computed directly from our stored match archive each time the page is served. Last computed 2026-09-23T01:44:29.672694+00:00.
OverUnderWeather Research Desk
Independent data analysis on public sports and weather records. Studies match historical game outcomes to archived game-window weather, apply pre-set sample and significance rules, and publish null results when that is what the data show. Editorial policy and corrections log.
Frequently asked
Does dew give the chasing team an advantage in the IPL?
Not measurably. Matches played in the heaviest dew conditions we can identify — an evening dew-point gap under 2°C — are won by the chasing team 51.6% of the time, and once each match is adjusted for both its season and its ground the gap from dry-air matches is +2.6 pts (t = 0.47 on 93 matches). That is indistinguishable from noise. The strongest test statistic anywhere on the page is 1.84, still short of the |t| ≈ 2 boundary we require.
Does dew add runs in the second innings?
No. Second-innings scoring in the heaviest dew band is +4.6 runs against dry-air matches (t = 1.32), and no dew or humidity band clears the noise boundary in either direction. Raw second-innings scoring is actually slightly lower in humid conditions than in dry air, because the most humid grounds are also the lower-scoring ones — which is exactly why every comparison here is adjusted for the ground as well as the season.
But chasing does win more often in the IPL, doesn’t it?
Slightly, and that is worth separating from the dew claim. Across 1,195 matches the chasing team wins 54.4% of the time and captains choose to field first 66.4% of the time — yet the toss winner only wins 51.5% of matches. So there is a small general chasing edge, and it does not get bigger when the air is at its most humid.
How is dew measured, given there is no dew gauge at a cricket ground?
Through two physical proxies, both stated openly. The first is the dew-point gap: the difference between air temperature and dew point during the second innings. When that gap closes towards zero the air is saturated and dew forms readily. The second is the humidity rise between the first and second innings. Neither is a direct observation of moisture on the outfield, and this is the study’s main limitation — a real effect confined to nights where dew actually settled could be diluted by nights that merely looked humid.
What about the start time of each match?
The match archive does not record start times, so the first innings is read at 20:00 local and the second at 22:00 local — the windows that fit the standard evening start used for the overwhelming majority of IPL matches. Afternoon matches are therefore misread, which adds noise. It cannot manufacture a false positive, but it is a genuine reason a modest real effect could be missed.
Which grounds are in the sample?
Every ground that has hosted the competition, 37 in all, including the overseas seasons in the United Arab Emirates and South Africa. 11 grounds have cleared the 40-match minimum individually and are shown separately. Matches at grounds we could not place to verified coordinates are excluded outright rather than estimated.
Is this a betting-market claim?
No. We hold no archive of closing IPL match odds or totals, so this study reports match outcomes and scoring only. Nothing here says whether the market prices a dew effect — only that we cannot find one in the results themselves.