This utilises a database of the last Test matches played, using past and current data to estimate the probability of future events. Each of those areas is given a positive or negative score in runs, measuring the performance of that team against that of an average Test team in the conditions present at that time.
The comprehensive historical database predicts the average performance of batsmen and bowlers in the position and role they are playing in.
The PlayViz function measures performance relative to averages that take into account extra variables. Runs saved and missed are totalled for each player, with a dropped catch measured at the value of the wicket that was missed according to the model of projected scores.
Fielding scores are adjusted by a system that rates the difficulty of a piece of fielding.
BatViz gives a measure of how difficult batting has been in the last 30 minutes of play. It shows how hard it is for the batsmen to survive and score.
The balls in this database that are the most similar to the delivery being measured are evaluated in terms of wickets taken and runs conceded, with a game aggregate built to provide a metric of current batting difficulty at that time.