the comment on the chart in the IBD 50 section today says: "sketches a rare but imperfect short stroke pattern".  doesnt say what the flaw is though.

This is from this article: education.investors.com/.../rare-birds-high-tight-flag-short-stroke.htm

Looks like the problem may be that it made a new high last week?

That's not the same for the short-stroke pattern, which is more aptly considered a follow-on pattern.

This formation — another that's relatively rare — occurs after a stock has made a major one-week gain. Instead of giving up much of its winnings, the stock pulls back modestly. It's similar to the high, tight flag in that shares hold most of their major gain.

The week after the price surge, the stock closes slightly higher or close to the prior week's close. At the same time, it typically doesn't make a new high.

The combination of a long price bar with a short one gives the appearance of the stroke of a pen, thus the pattern's name: short stroke.

Once the stock makes new highs, it's your signal to buy shares.