Dirk Pitt vs Sigma Force
Two thriller series side by side, straight from the catalog data: Dirk Pitt is the longer series (25 books vs 14 books); Sigma Force is the more recent one, starting in 2004. There's no wrong answer — pick the shape that fits your reading appetite, and Shelfmark will keep your place in either (no account needed).
| Statistic | Dirk Pitt | Sigma Force |
|---|---|---|
| Author | Clive Cussler | James Rollins |
| Books | 25 | 14 |
| Published | 1973–2019 | 2004–2019 |
| Books per year | 0.5 | 0.9 |
| Start with | The Mediterranean Caper (1973) | Sandstorm (2004) |
| Reading order | Full Dirk Pitt order → | Full Sigma Force order → |
Numbers come from the Shelfmark catalog (Wikidata + Open Library). "Books per year" is catalogued books divided by the publication span — a rough cadence, not a quality score.