Riding high in April, shot down in May

Somerset CCC have recently experienced the peaks and troughs of cricket fortune.

A fortnight ago Middlesex declared at 4/600, which Somerset chased down comfortably thanks to a triple century from Justin Langer and three other hundreds, not to mention the five Middlesex bowlers who conceded more than a hundred apiece .

In the game being played at the moment Derbyshire lost their first two wickets before scoring a run, but then added a further 601, losing only another six wickets in the process, eventually declaring at 8/801. On this occasion another former Australian player, Simon Katich, led the way with 221. There were three other batting, and five bowling, centuries.

As I post after the second day's play Somerset are 4/107, 694 runs behind with 6 wickets in hand.

Any suggestions as to causes? Good batting, poor bowling, small ground....?