<b>3 shared URLs is the cleanest clustering threshold</b>

<b>3 shared URLs is the cleanest clustering threshold</b>
We tested SERP-overlap clustering on 2,400 queries, grouping keywords when their top 10 results share pages. The question is how many shared URLs justify one page.

— 2 shared URLs: 31 percent false merges ▇▇▇▇▇▇
— 3 shared URLs: 12 percent false merges ▇▇▇
— 4 shared URLs: 6 percent false merges ▇▇
— 5+ shared URLs: 3 percent but misses 40 percent of real pairs

Three is the sweet spot where merges stay accurate without splitting topics into dust. So what: cluster at 3 shared results, then hand-check the cluster head before committing one page to multiple keywords.

<i>Benchmark of the week:</i> the 3-URL rule cuts bad merges to 1 in 8.