The 49ers have lost eight consecutive games in Seattle and if their defense doesn’t improve, the losing streak could extend to nine. The 49ers have allowed an average of 35 points a game during the past three games and they have allowed an average of 26.7 points a game during the second half of the season. Those numbers mark a dramatic increase compared to the first eight games, when the 49ers allowed an average of 12.7 points a game. Part of the reason has been the 49ers’ schedule, which has been much more difficult in the second half. Five of the 49ers’ seven opponents currently have winning records during the second half. The 49ers faced one team with a winning record in the first half. The 49ers can look to their pass rush as another reason for the performance decline. They’re not reaching the quarterback as often as they did earlier in the season. The 49ers led the NFL with 45 sacks through the first 12 weeks of the season. They have posted just three total sacks in the past four weeks.