Sentence:  The most persistent tormentor was Alex Oxlade-Chamberlain, who scored a hat-trick in last month's corresponding fixture in Iceland. His ability to run at defences is instantly striking, but it is his clever use of possession that has persuaded some <WSD>shrewd</WSD> judges that he is an even better prospect than Theo Walcott. 
Meaning of the word marked with <WSD> tags:  Knowledgeable, intelligent, keen.