There’s more to come, but as of Monday, July 9, I’ve seen 61 estimates — 28 from the professionals who cover Apple for banks and brokerage houses and 33 from a rapidly growing contigent of independent Apple analysts — bloggers, long-term investors and at least one day trader who has started a multimillion-dollar Apple hedge fund.

As usual the indies are more bullish than the pros, but the iPad gap is unusually wide this quarter. With iPhone sales expected to slow in advance of a new model next fall, iPad unit sales — which were lower than some analysts expected in Q2 — could be the key to Apple’s Q3 results.

Among the professionals, the estimates range from low of 12.68 million iPads from Wedbush’s Scott Sutherland to a high of 18.5 million from Cowan’s Matthew Hoffman. The average estimate from this group is 15.07 million.

The average among the independents is 19.96 million — 4.89 million (32%) higher than the pros and more than double the 9.25 million sold in the same quarter last year. The low estimate in this group was 17.7 million from Alexis Cabot, a American ex-pat living in Rome, and the high was the 24 million submitted by Asymco‘s Horace Dediu.

We like to keep an especially close eye on the six independent analysts with the best track record over the past seven quarters. Their consensus: 18.75 million iPads, a year-over-year increase of 102.8%.

We’ll find out who was closest to the mark when Apple reports its earnings after the markets close on Tuesday, July 24.

Below the fold: The analysts’ individual estimates, with the pros in blue and the amateurs in green. Note the sharp separation of the colors. [Updated July 9 to include estimates from four more independents (Sunil Shah, Corey Forsberg, Chas McKenna and Robert Eversz].

For the first time in the nearly four years I’ve been gathering these estimates, the independents outnumber the pros. This is thanks largely to the work of Robert Paul Leitao, who with his wife Sandy rides herd over nearly 280 Apple enthusiasts at The Braeburn Group, a private discussion board open to serious Apple investors willing to post under their real names. You can reach Leitao through his blog, Posts at Eventide.