By making runs and taking wickets!
Shield cricket is always revealing but ever the more important when national selection is afoot. Victoria is showing why it is justified in bemoaning a lack of national representation by grabbing first innings points against NSW. Hussey (the good one) has made another ton against a team featuring Watson, Hughes, Clarke, Clark, Haddin and Jacques. While the big V relies more on a well-gelled side featuring one test player but several aspirants, NSW is a mish-mash of over-achievers out to prove themselves at all costs.
Meanwhile Qld is showing it may not have much to offer the test arena right now but it is still a formidable unit. Harris has booked his flight (well, bus ride as he'll be home) to Brisbane while Captain Superannuation Ponting has missed out on getting some time in the middle.
Eyes will be on state cricket like never before this season with unparalleled scrutiny of the national side. This can only be a good thing as whatever your opinion of the makeup of Australia's test team (really the only one that matters); there has to be players warranting selection and up to the task of international cricket - unless of course selectors' hands are forced. CA has one eye on the World Cup and as such is delaying addressing the test side which could prove costly when the surprise retirement of old age pensioners from its ranks occurs. Perhaps Dad's Army could bat in a wheelchair but it looks ugly when they're making their way around home in gophers.