How many redirects on a redirect can you have?

[Manifestation]

Since 2007 the best keywords for a good rank in seo have changed.

In some cases we have changed urls to maintain a good ranking.

That was 2 years ago ... and now we see we need to upgrade the keyword phrase we use and are thinking about changing the urls once again to keep our ranking.

It seems absurd to have a redirect for your redirected page.

Are there different ways to approach updating your keyword phrases without the 301 redirect?

For example, it has been 2 years since we did a 301 redirect on a group of our pages. Are we better off having the original url deleted (which has been up since '07) or is it better to redirect the original page and the redirected page to the newest page?

We already incorporate the updated keyword phrase changes into our titles, images and body copy to reflect the changes.

Thanks

[AlexMcKee]

In 2011 Matt Cutts advised that Google does limit on redirect chains - he indicated the Googlebot won't follow more than around 3 or 4. No limit on the total number of single-level 301s.

In your specific situation I would redirect both the original and the first replacement to the new replacement so that users and bots can reach the new page in a single redirect hop.