Mystery thrush

There are times when I'm not at all sure that I should post a photograph, even one I think is the best of the day and definitely one I like. My reluctance is not on artistic grounds but rather on natural history grounds. Here's the conundrum. I spotted this thrush—I'm sure it's a member of the Thrush family and fairly close kin to a Robin—in the shrubs at the back end of the doomed field. I was walking the circumference in hopes of spotting the last of the odonates, but the meadowhawks and Shadow Darners may have called it a season. Or, at least, a day. But a couple of these thrushes made up for my disappointment by putting on a show within camera range. That's the good part—and a good picture. The bad part is that, when I got home and examined the haul, I couldn't come up with a definite identification. It's not a Wood Thrush, our summer singer and now on migration. It doesn't seem red-brown enough to be a Hermit Thrush, and it wasn't bobbing its tail—a Hermit characteristic. It doesn't have "spectacles," so it's not a Swainson's. That leaves, by default, either a Bicknell's or a Gray-cheeked, both difficult to tell apart. If you can pin it down, let me know.