Ryanverse vs Sigma Force
Two thriller series side by side, straight from the catalog data: Ryanverse is the longer series (28 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 | Ryanverse | Sigma Force |
|---|---|---|
| Author | Tom Clancy | James Rollins |
| Books | 28 | 14 |
| Published | 1984–2018 | 2004–2019 |
| Books per year | 0.8 | 0.9 |
| Start with | The Hunt for Red October (1984) | Sandstorm (2004) |
| Reading order | Full Ryanverse 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.