Bourne vs Sigma Force
Two thriller series side by side, straight from the catalog data: 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 | Bourne | Sigma Force |
|---|---|---|
| Author | Robert Ludlum | James Rollins |
| Books | 14 | 14 |
| Published | 1980–2017 | 2004–2019 |
| Books per year | 0.4 | 0.9 |
| Start with | The Bourne Identity (1980) | Sandstorm (2004) |
| Reading order | Full Bourne 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.