Bilateral Cricket Series Formats: How Test, ODI, and T20I Series Are Structured
How bilateral cricket series are structured across all three formats — the standard lengths for Test series (2, 3, 4, and 5 matches), ODI series (3–5 matches), and T20I series (3–5 matches), how scheduling works, and why the Five-Test series remains the pinnacle format of bilateral cricket.
A bilateral series is a cricket tour where two nations play a scheduled sequence of matches against each other — as distinct from multi-team tournaments or ICC events. The bilateral series is the foundation of international cricket's commercial and competitive calendar, governed by the ICC Future Tours Programme (FTP), which plans schedules four years in advance. Each format has standard series lengths, though the lengths vary significantly based on the commercial importance of the matchup, the length of the tour window, and the preferences of the host board.
Test Series: 2, 3, 4, and 5 Matches
Test series are structured in varying lengths depending on the significance of the contest and scheduling constraints. A five-Test series is the longest bilateral format and is now reserved for cricket's most commercially and historically significant rivalries: the Ashes (England vs Australia), England's home series against India, and occasionally Australia vs India or England vs South Africa. A three-Test series is the most common structure for bilateral tours between major Full Members: India vs South Africa, New Zealand vs Sri Lanka, West Indies vs England. Two-Test series are scheduled for tours where calendar constraints limit the available time window, or for matches between lower-ranked Full Members. Four-Test series, once common (England vs West Indies in the 1980s and 1990s), are now rare. The series is won by the team winning the most matches; if tied, the series is drawn.
ODI Series: The 3-to-5 Match Structure
ODI series are typically either three or five matches, with five-ODI series reserved for the most commercially significant bilateral tours. The home team always wins the series if they win three out of five, or two out of three. White-ball bilateral series often incorporate both ODIs and T20Is in the same tour window, sometimes interleaved with the Test matches. A typical modern bilateral tour might run: first T20I, second T20I, third T20I, then break, first Test, second Test, third Test, then first ODI, second ODI, third ODI. This scheduling maximises commercial value by ensuring the more commercially accessible white-ball formats (higher broadcast audiences in some markets) are interspersed across the tour.
T20I Series: The Fastest Growing Bilateral Format
T20I bilateral series are the fastest-growing component of the FTP calendar. From being an occasional novelty in the mid-2000s, T20I series have become a standard feature of all bilateral tours, typically running three to five matches. Some bilateral tours now include more T20I matches than Tests — India's tours of Australia and England in recent years have featured three Tests and three or five T20Is, reflecting the commercial demand for the shortest format. T20I series results feed into ICC T20I team rankings and, during cycle years, contribute to T20I World Cup qualification seedings. For teams without Test status (ICC Associates), T20I bilateral series are often the primary competitive format available.
The Five-Test Ashes: Bilateral Cricket's Pinnacle
The Ashes — contested between England and Australia every two years (alternating home and away) — remains the only bilateral series still routinely played across five Tests, making it unique in the modern FTP landscape. The commercial and historical prestige of the Ashes (continuously played since 1882, centred on the famous urn containing the burned bails from the 1882 match) justifies the five-Test structure that is now rare elsewhere. A five-Test Ashes series running to its conclusion provides 25 potential days of Test cricket — making it one of the longest sporting events in the world. The length allows for momentum shifts, changing conditions across venues, and genuinely substantial sample sizes of competitive cricket that shorter series cannot replicate.
Frequently asked questions
Has the reduction in Test series lengths — from four and five Tests being common to two and three Tests being standard — damaged the quality or significance of bilateral Test cricket, and could longer series be revived commercially?
The reduction in Test series lengths since the 1990s has had genuine consequences for the quality and character of bilateral Test cricket, and the case for longer series is stronger than the current scheduling consensus acknowledges — though commercial constraints that drove the shortening are real. What longer series provide that shorter ones don't: a five-Test series generates enough playing time for conditions to change significantly across venues, for injured or indisposed players to be replaced and for the team that adapts better to win despite an early-series setback. The 1981 Ashes (Botham's Ashes) featured England losing the first Test, drawing the second, and then winning three consecutive Tests to win the series 3-1 — a narrative arc impossible in a three-Test series where losing the first match puts a team in a near-impossible recovery position. A three-Test series is won by the team that peaks earlier; a five-Test series often rewards the team with greater depth and adaptability. Why series shortened: the ICC FTP's primary driver is commercial revenue maximisation. A India-England series generates revenue roughly proportional to the number of days of cricket — but an England-Zimbabwe series does not. With all Full Members having FTP obligations to host each other on a regular cycle, and with the calendar also hosting T20I bilateral series (high revenue per playing day) and ICC tournaments, the only flexible element is Test series length. Boards have economised on lower-revenue series by reducing them to two Tests. The revival case: some cricket executives and analysts have argued for a tiered FTP that explicitly preserves five-Test series between the top six teams and reduces the obligation to play Tests against less commercially viable opponents. This would preserve the longer-format experience where it has most value. ICC's World Test Championship has added competitive meaning to bilateral series, slightly improving the case for longer series. But the fundamental commercial reality — T20 franchise leagues competing for the same calendar space and player availability — makes the revival of four or five-Test series below the Ashes level unlikely in the current structure.