GoogleAlgorithmUnconfirmedHigh impact
Jagger
Multi-phase autumn 2005 update aimed at reciprocal links, paid links and link farms, rolled out in roughly three stages.
What changed
Jagger rolled out in several distinct phases through the autumn of 2005 and mainly devalued manipulative link patterns: reciprocal link schemes, purchased links and low-quality directories. Because it landed in waves, sites saw repeated shifts over several weeks rather than a single drop. Google did not announce it; only the month range is documented, so the start date is set to the first of October 2005.
Not confirmed by the engine. This entry documents a change that was widely observed and reported, but never officially acknowledged. Treat the dates as approximate and the mechanism as inferred.
Timing
Rollout began 1 October 2005. No completion date was announced. Rankings typically remain unstable for the whole rollout window, so measurements taken inside it are not a reliable read on the outcome.