The best -- and healthiest -- of Colin Kaepernick in 2013 is yet to come.

That's probably the most significant conclusion/prediction I can make about the 49ers season so far, and the clearest way to view them right now.

Schedule fact: The 5-2 49ers can extend their winning streak to five games by beating winless Jacksonville in London on Sunday.

After that, the 49ers get their bye week and don't play again until Carolina comes to Candlestick Park on Nov. 10.

So this is as good a time as any to take a measure of where the 49ers have been, and where they're going in 2013 ...

  • For practical evaluation purposes, the 49ers' 2013 season could split into sections:

    LONDON, ENGLAND - OCTOBER 25:  San Francisco 49ers quarterback Colin Kaepernick warms up during a San Francisco 49ers training session at Allianz Park on
    LONDON, ENGLAND - OCTOBER 25: San Francisco 49ers quarterback Colin Kaepernick warms up during a San Francisco 49ers training session at Allianz Park on October 25, 2013 in London, England. (Photo by Jamie McDonald/Getty Images) ( Jamie McDonald )

    Part A) When Kaepernick was limited with a foot injury, wobbling through up/down performances in Weeks 2 through 6, and the 49ers did not look like a team that matched up well with Seattle atop the NFC West ...

    And now Part B) When Kaepernick is getting healthy again, confident again, and possibly ready to beat Seattle in Candlestick in December and maybe take the NFC West again.

    There might be a very ominous Part C) if Kaepernick gets nicked up again, or hurt more seriously and Colt McCoy has to play meaningful snaps.

    But for now, it's not a stretch to theorize that Kaepernick suffered a foot injury in the Week 1 victory over Green Bay and was a much less explosive player while he worked through the problem.

    If you take that theory further, you could point out that Kaepernick probably got back close to 100 percent last Sunday -- when he finally started breaking loose on the read-option and scored his first rushing touchdown of the season.

    It's more than just Kaepernick's relative success with -- and the 49ers' interest in running -- the read-option, too.

    Several NFL sources have suggested that Kaepernick seemed to be having trouble going from his plant (right) foot to his land (left) foot during his throwing motion, which could be what was sending many of his passes sailing high.

    In the 2012 regular season, he completed 62.4 percent of his passes, averaged an incredible 8.3 yards per attempt and threw only three interceptions in 218 attempts.

    This season he is completing only 56.6 percent of his passes, his YPA is down to 7.8, and he has thrown five interceptions in 182 attempts.

    A theoretically healthy/nonhealthy Kaepernick breakdown:

  • Kaepernick vs. Green Bay and Tennessee: 66.7 percent completion percentage, three touchdown passes, zero interceptions, 18 rushes for 90 yards, one rushing TD.

  • Kaepernick in Weeks 2 through 6: 51.6 percent, five TD passes, five interceptions, 24 rushes for 150 yards, zero rushing TDs.

    Presuming Kaepernick has a light time of it against Jacksonville, his foot (whichever one is hurt) should be as healed as it's ever going to be after the bye week, and Kaepernick should look more and more like he did in 2012 ... or better.

    Plus, the 49ers will get Mario Manningham back soon and Michael Crabtree eventually, finally adding realistic receiving options beyond Anquan Boldin and Vernon Davis.

  • The 49ers went back to the running game and Frank Gore after their two-game losing streak, and that stabilized everything.

    They'll need Kaepernick doing extra things in the tougher games -- especially against Seattle -- but for now, running the ball often and well has put the 49ers back on solid ground.

    In this photo provided by the NFL, San Francisco 49ers quarterback Colin Kaepernick, centre, stretches during practice at the Allianz Park Stadium, London,
    In this photo provided by the NFL, San Francisco 49ers quarterback Colin Kaepernick, centre, stretches during practice at the Allianz Park Stadium, London, Friday, Oct. 25, 2013. The San Francisco 49ers are to play the Jacksonville Jaguars in game two of the NFL International Series at Wembley Stadium in London on Sunday, October 27. (AP Photo/Sean Ryan, NFL) ( Sean Ryan )

    They averaged over 30 rushing attempts per game in the 2011 and 2012 regular seasons but averaged only 25.7 rushing attempts in the first three games of 2013, losing two of them.

    They've averaged 38.8 rushing attempts during their current four-game winning streak and have out-rushed opponents 698-328 in those games.

    The 49ers defense has adapted to life -- for however long it lasts -- without star linebacker Aldon Smith.

    How have they done it? Because NaVorro Bowman has been one of the best players in the NFL, because Eric Reid has become an instant impact safety and because Tramaine Brock has won the nickel back job with a slew of interceptions.

    The 49ers are 4-0 and have turned in defensive gems against St. Louis, Houston and Tennessee (with a little shakiness against Arizona) since Smith fatefully played in that loss to the Colts only two days after his DUI arrest.

    Coach Jim Harbaugh said recently that Smith might be back within a few weeks; general manager Trent Baalke told reporters in London that the 49ers are hopeful but have no exact timetable on Smith's potential return.

    So far, the 49ers defense is playing perfectly well without him, mostly by turning up the take-away machine -- they've produced 12 of their 15 turnovers in the last four games.

    If Smith can get back relatively soon and add to the defense, they'll be that much better. If he doesn't, it's pretty clear that they can go on without him.

    Now all that's left is the second half of the season, that Dec. 8 game against Seattle, and everything the 49ers have been building -- and adjusting to -- in the first section of 2013.

    For more, see Tim Kawakami's Talking Points at blogs.mercurynews.com/kawakami. contact him at tkawakami@mercurynews.com. Follow him on Twitter at twitter.com/timkawakami.

  • Focus is on fifth straight victory. PAGE 4

  • Goodell talks about troubled linebacker Aldon Smith. page 4