A quick observation of Matthew Stafford and how he played in the Detroit Lions' 34-9 loss in Week 12:

Matthew Stafford is coming off a career-worst 39.1 completion percentage Sunday against the New England Patriots, and if his history is a guide, the Lions could be in trouble the rest of the way starting Thursday against Chicago.

In his career, Stafford is 4-12 in Weeks 13-17, including a 1-9 mark down the stretch in the past two seasons. His statistics also have showed significant drop-off as the season enters its final five weeks. Over the past three seasons, his QBR from Weeks 13-17 has dropped from 83.0 in 2011 to 49.6 in 2012 to 29.6 in 2013. His completion percentage has also been lower each season from 2011 to 2013, including a 57.4 percent mark last year.

After a 15-to-3 touchdown-to-interception ratio in 2011, he dipped to .86 touchdowns per interception in 2012 and .71 touchdowns per interception in 2013. Considering the way Detroit’s offense is struggling right now -- no offensive touchdowns in eight quarters -- how Stafford adjusts during the season’s final five weeks will be critical not only for the Lions’ playoff chances but also for his effort in turning around a disturbing trend.