Home advantage in Test cricket is unusually large compared with other sports, and pitch preparation is the main reason. The mechanism is subtler than simply producing a surface the visiting side dislikes.
Preparation is a set of adjustable choices
Groundstaff control the amount of grass left on the surface, how much moisture remains in it, and how heavily the pitch has been rolled beforehand.
Grass cover holds the surface together and helps seam movement, while a shaved, dry pitch breaks up earlier and assists spin from the second day.
None of these settings is exotic. They are ordinary groundskeeping decisions that happen to have direct competitive consequences.
Boards prepare for the attack they own
A side whose strength is a battery of fast bowlers benefits from surfaces with pace and carry, and its home grounds tend to produce them.
A side built around spin benefits from dry surfaces that turn early, and preparation instructions reflect that even when they are never stated publicly.
The effect is not corruption but alignment, since the same groundstaff prepare surfaces for domestic cricket that produced those bowlers in the first place.
Familiarity matters more than severity
The larger advantage is informational. Home players have spent careers reading local surfaces and know how quickly a particular ground's pitch will deteriorate.
That knowledge shapes the toss decision, the batting tempo and the point at which a captain turns to spin, all of which visiting sides must estimate.
A moderately helpful pitch that the home side understands is worth more than an extreme one that surprises both teams equally.
Extreme surfaces carry a penalty
Governing bodies rate pitches after matches and can sanction grounds for surfaces judged unfit or unduly weighted towards one discipline.
Matches that end inside two days attract scrutiny, and repeated sanctions can cost a venue its status as a Test ground.
The constraint keeps preparation within a range, so boards tune surfaces towards their strengths rather than engineering conditions that would be penalised.
Touring schedules make it worse
Visiting sides increasingly arrive with little time for warm-up matches, because international calendars have compressed the space between series.
Without meaningful practice on local surfaces, players adapt during the Tests themselves, which usually means adapting after losing the first one.
Home advantage has therefore grown partly for scheduling reasons that have nothing to do with the pitches at all.
