Playing with statistics can be like traipsing across a minefield: One wrong step and you're singing falsetto.

I had that feeling when I pulled a Tampa Bay area report by national housing consultant First American CoreLogic and compared its home sales statistics with those of the Florida Association of Realtors.

Realtors said October home sales rose 11 percent, from 1,814 in 2007 to 2,021 in 2008. First American said sales fell 12 percent, from 2,497 in October 2007 to 2,200 in October 2008.

What to make of this? I'm not too concerned about the October 2008 figures. Realtors' and First American's numbers are in the general ballpark. Even their median sales price corresponded pretty well. Realtors reported $152,300 while First American reported $155,000.

But that October 2007 number is suspicious. How could Realtors report 27 percent fewer sales than First American? If I had to guess, I'd say Realtors were more accurate.

Think about it. As a trade group for the home selling industry, the Realtor association has the greater incentive to fudge sales on the upside. But it didn't.

One possibility is that Realtors, by not counting by-owner and non-Mulitple Listing Service sales, missed a boatload of transactions in October 2007. But 683 sales - the difference in the two counts -seems too high.

Here's a chart from First American: Download corelogicchart.bmp