blot one’s copybook

ザッケローニ監督は海外組の力を心待ちにしています。最近のW杯予選では２敗を喫し，自身の不敗記録に泥を塗ってしまいました。記事にあるblot one’s copybookは，通例，男が「（軽率なことをして）経歴を汚すような失敗をする」という意味です（『ジーニアス英和辞典』第４版，大修館書店）。blotは以前にも取り上げられているので，参照してください。（Sugiuchi）
Cf: http://d.hatena.ne.jp/A30/20120220/1329727680
Zaccheroni needs European contingent to hit ground running
Alberto Zaccheroni may have blotted his copybook with defeats in Japan's last two competitive matches, but the national team manager will only have eyes for the here and now as he begins his preparations for the final round of World Cup qualifiers this week.
Zaccheroni on Friday names his squad for next Wednesday's warmup friendly against Azerbaijan in Shizuoka, with the Italian set to draw heavily from his Europe-based contingent ahead of next month's qualifiers against Oman, Jordan and Australia. Losses to North Korea and Uzbekistan at the end of the previous round cost Zaccheroni the unbeaten record he had held since taking over in September 2010, but with the majority of his players arriving straight from the end of the European club season, the dynamic this time will be significantly different.
http://www.japantimes.co.jp/text/sp20120517am.html