FWIW, a few sets of figures:
Caddick was woeful in his debut series in 1993, with the exception of one second-innings spell at Trent Bridge (3-32 off 16) which almost won the game. In his second series in West Indies in 1994 he bowled OK in both innings' in the First Test, then had his classics in the Third and Fourth Tests - wicketless in both first-innings', big hauls in both second-innings'. Then poor (like everyone) in the Fifth Test at The ARG.
He played just 1 Test in the next 3 years (doing no more than OK), then came back in in the Second and Third Tests in New Zealand, bowling well and reasonably respectively.
He then had a pretty good Ashes series in 1997, just one out-and-out poor game out of five, and best performances in more first-innings than second-. Then another OK tour of West Indies - poor in the First Test, excellent (especially in the first-innings) in the Second, good as a backup performer in the Fourth, and poor again at The ARG in the Fifth.
Surprisingly, if you exclude his woeful debut series, he averaged 27.62 between 1994 and 1998. This is better than I'd always thought. The thing was, I suppose, we were all hoping he could be the sort of bowler who'd average 23-24.
This he did indeed do in his next phase. What was most marked was the improvement in his economy-rate - in said aforementioned phase he'd conceded 3.09-an-over - between the New Zealand series in 1999 and the First Test against Pakistan in 2001, he went for just 2.58-an-over. This was the time his first- and second-innings performances were so markedly different - 31.32 in the first-innings, 15.15 in the second-. Given how good his performances were, I think we can more than forgive the slightly less-than-ideal first-innings performances, as others were mostly doing the work there.
Then came the final phase, that disappointed me so. Again, the problem wasn't strike-rate - his economy-rate (3.65-an-over) was simply not good enough, for someone whose real strength in the previous phase had been accuracy. This continued after his return in 2004, when I'd have hoped that had he not picked-up that serious injury he'd have improved rather than worsened.