The heralded select portion of the Keeneland September Yearling Sale will undergo another overhaul for 2013, with the previously boutique offerings now scheduled to span the entire four-day opening week with approximately 950 yearlings cataloged.

Under the new format announced Wednesday, the four "Book 1" sessions will run Monday-Thursday (Sept. 9-12) starting at noon each day, with "Book 2" picking up on Saturday and Sunday at 10 a.m. following the traditional dark day on Friday.

Books 3-6 will be September 16-20, with those sessions beginning at 10 a.m.

Last season, Book 1 and Book 2 comprised a single catalog, with the select portion taking place in one Monday evening session. In previous years, select sessions were held over the first two days of the sale.

Last year's tweak prompted some buyers and sellers to speculate that since the level of quality between Book 1 and Book 2 horses had become more negligible in the current market, the select portion would eventually disappear entirely.

"We talked to several customers from the year before last to this year and I think the consensus was they would be part of a standard book rather than a small one," said Walt Robertson, Keene-land's vice president of sales. "Their horses sold just as well in Book 2 as they did in Book 1 and, from a logistics standpoint, it's just more convenient.

"Book 1 is still going to be a lot of nice horses and big pedigrees as Book 1 and 2 were last year. We will inspect those horses and we're looking for nice horses."

The 2012 September Yearling Sale posted double-digit gains in average and median with the overall gross of $219,781,500 dipping 1.66 percent after selling 405 fewer horses than the previous year.

Keeneland officials hope making Book 1 a more drawn-out but more inclusive affair results in greater residual buying strength deeper into the auction.

"I think the second week was great last year and I see no reason it won't be this year," Robertson said. "They (the agents) worked it awfully hard last year, and this year they can do it all in one spot. We won't have one consignor's horses in two places early like that."

Alicia Wincze Hughes: (859) 231-1676. Blog: horseracing.bloginky.com. Twitter: @horseracinghl.