Conditions are treated as an afterthought in previews and function as a genuine variable. Wind, rain and a poor surface do not affect both teams equally, because they penalise some styles far more than others.
Short passing needs a reliable surface
Building through midfield with quick combinations depends on the ball arriving where it was aimed, at a predictable speed and height.
A heavy or uneven pitch introduces error into every pass, and the errors compound across a sequence that requires several accurate touches.
Direct play is affected far less, since a long ball into a contested area tolerates imprecision that a short pass into feet does not.
Wind is the most underrated factor
Strong wind makes goalkeepers reluctant to play short, alters the flight of crosses and set-piece deliveries, and makes pressing the ball carrier riskier.
It is also directional, so the same team faces different conditions in each half and the pattern of a match can invert at the interval.
Teams that press high are particularly exposed, because a mishit clearance travelling further than expected turns their line into a liability.
Rain changes the timing of everything
A wet surface speeds the ball up and lengthens sliding distances, which rewards early shooting and makes committed defending more dangerous.
Handling becomes harder for goalkeepers, and shots from distance become more valuable than the same shots on a dry evening.
Persistent rain on a soft pitch produces the opposite effect once the surface holds water, slowing the ball and exhausting players faster.
Pitch quality varies more than expected
Grounds differ in drainage, in whether the pitch is shaded for much of the day and in how heavily it is used by other events.
Some surfaces deteriorate visibly across a season, and a January fixture at such a ground is a different proposition from a September one.
Hybrid and fully artificial surfaces introduce further differences in bounce and grip that visiting teams train on rarely.
What it means for a preview
Conditions compress the difference between teams, which favours the underdog in almost every case regardless of the specific weather.
The direction of the effect is predictable once both teams' styles are known, which makes it one of the few adjustments that can be made confidently.
Forecasts are available days ahead and are consulted by the coaching staff. There is no reason a preview should ignore what the teams are planning around.