<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
	>

<channel>
	<title>whaack</title>
	<atom:link href="http://ztkfg.com/feed/" rel="self" type="application/rss+xml" />
	<link>http://ztkfg.com</link>
	<description>198.211.113.164 // 6326 273B 61A7 00AF 4CD9 5A7B 8C6C AB19 24A6 4DEC</description>
	<pubDate>Thu, 26 Mar 2026 16:19:36 +0000</pubDate>
	<generator>http://polimedia.us</generator>
	<language>en</language>
	<sy:updatePeriod>hourly</sy:updatePeriod>
	<sy:updateFrequency>1</sy:updateFrequency>
			<item>
		<title>Notes on Groups and their Automorphism Group</title>
		<link>http://ztkfg.com/2026/03/notes-on-groups-and-their-automorphism-group/</link>
		<comments>http://ztkfg.com/2026/03/notes-on-groups-and-their-automorphism-group/#comments</comments>
		<pubDate>Thu, 26 Mar 2026 16:19:36 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Misc]]></category>

		<category><![CDATA[Reflection]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=554</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==Every group1 has an intrinsic group, its automorphism2 group, which is the set of the group's automorphisms under function composition. At first, I thought the automorphism group was every permutation of the set of the elements in the original group. Let’s see why this is not so, and let's see what characteristics the automorphism group [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==Every group1 has an intrinsic group, its automorphism2 group, which is the set of the group's automorphisms under function composition. At first, I thought the automorphism group was every permutation of the set of the elements in the original group. Let’s see why this is not so, and let's see what characteristics the automorphism group [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/03/notes-on-groups-and-their-automorphism-group/feed/</wfw:commentRss>
		</item>
		<item>
		<title>Two times where I missed a trump promotion</title>
		<link>http://ztkfg.com/2026/01/two-times-where-i-missed-a-trump-promotion/</link>
		<comments>http://ztkfg.com/2026/01/two-times-where-i-missed-a-trump-promotion/#comments</comments>
		<pubDate>Sat, 24 Jan 2026 20:47:16 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Contract Bridge]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=553</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




will22&#9824;︎J8&#9829;︎7&#9830;︎107&#9827;︎4



MarciaJoy&#9824;︎&#8212;&#9829;︎&#8212;&#9830;︎J86&#9827;︎KQ7

nrollier&#9824;︎&#8212;&#9829;︎Q10&#9830;︎&#8212;&#9827;︎A1065



WillHaack&#9824;︎&#8212;&#9829;︎J8&#9830;︎Q&#9827;︎J98





On this hand clubs were trump and RHO was the declarer, and my partner led the J of spades, declarer pitching a heart. I failed to pitch the queen of diamonds. Since the dummy only had diamonds besides his high trumps after ruffing, he would have to give me a trump promotion when he played [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




will22&#9824;︎J8&#9829;︎7&#9830;︎107&#9827;︎4



MarciaJoy&#9824;︎&#8212;&#9829;︎&#8212;&#9830;︎J86&#9827;︎KQ7

nrollier&#9824;︎&#8212;&#9829;︎Q10&#9830;︎&#8212;&#9827;︎A1065



WillHaack&#9824;︎&#8212;&#9829;︎J8&#9830;︎Q&#9827;︎J98





On this hand clubs were trump and RHO was the declarer, and my partner led the J of spades, declarer pitching a heart. I failed to pitch the queen of diamonds. Since the dummy only had diamonds besides his high trumps after ruffing, he would have to give me a trump promotion when he played [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/two-times-where-i-missed-a-trump-promotion/feed/</wfw:commentRss>
		</item>
		<item>
		<title>There's 2 pitches for the clubs!</title>
		<link>http://ztkfg.com/2026/01/theres-2-pitches-for-the-clubs/</link>
		<comments>http://ztkfg.com/2026/01/theres-2-pitches-for-the-clubs/#comments</comments>
		<pubDate>Fri, 23 Jan 2026 02:39:26 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Contract Bridge]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=552</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==





18


will22&#9824;︎AJ543&#9829;︎Q10&#9830;︎Q854&#9827;︎Q9


BBO Viewer
Bridge Solver




ralanchase&#9824;︎762&#9829;︎J95&#9830;︎107&#9827;︎87432




W
N
E
S





P
1&#9829;︎
2&#9830;︎


P
2&#9824;︎
P
3&#9830;︎




rzinman133&#9824;︎Q1098&#9829;︎K8743&#9830;︎K&#9827;︎AK10



WillHaack&#9824;︎K&#9829;︎A62&#9830;︎AJ9632&#9827;︎J65

3&#9830;︎ S





Here's a hand that I played atrociously.
LHO lead a low heart. Naturally, I played him for the jack, and consequently caught the king. Now I played the king of spades, crossed to the dummy with a heart, and pitched a heart with the ace of spades. What a mistake! I was always [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==





18


will22&#9824;︎AJ543&#9829;︎Q10&#9830;︎Q854&#9827;︎Q9


BBO Viewer
Bridge Solver




ralanchase&#9824;︎762&#9829;︎J95&#9830;︎107&#9827;︎87432




W
N
E
S





P
1&#9829;︎
2&#9830;︎


P
2&#9824;︎
P
3&#9830;︎




rzinman133&#9824;︎Q1098&#9829;︎K8743&#9830;︎K&#9827;︎AK10



WillHaack&#9824;︎K&#9829;︎A62&#9830;︎AJ9632&#9827;︎J65

3&#9830;︎ S





Here's a hand that I played atrociously.
LHO lead a low heart. Naturally, I played him for the jack, and consequently caught the king. Now I played the king of spades, crossed to the dummy with a heart, and pitched a heart with the ace of spades. What a mistake! I was always [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/theres-2-pitches-for-the-clubs/feed/</wfw:commentRss>
		</item>
		<item>
		<title>bitcoindexplorer.com temporarily offline</title>
		<link>http://ztkfg.com/2026/01/bitcoindexplorercom-temporarily-offline/</link>
		<comments>http://ztkfg.com/2026/01/bitcoindexplorercom-temporarily-offline/#comments</comments>
		<pubDate>Wed, 21 Jan 2026 16:17:13 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Bitcoin]]></category>

		<guid isPermaLink="false">http://ztkfg.com/2026/01/bitcoindexplorercom-temporarily-offline/</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==Due to my tardiness in combating what seems to be a low-effort DoS against my public blockexplorer, bitcoindexplorer.com (aka explorer.ztkfg.com) is offline. You can still access it via the irc interface in jwrd's irc channel, see jfxpt.com. Someone seems to have rented an AWS box and used Claude AI with a prompt such as:
Generate and [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==Due to my tardiness in combating what seems to be a low-effort DoS against my public blockexplorer, bitcoindexplorer.com (aka explorer.ztkfg.com) is offline. You can still access it via the irc interface in jwrd's irc channel, see jfxpt.com. Someone seems to have rented an AWS box and used Claude AI with a prompt such as:
Generate and [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/bitcoindexplorercom-temporarily-offline/feed/</wfw:commentRss>
		</item>
		<item>
		<title>BridgeMaster Level 4 B-30, Stumbling on a Trump Squeeze</title>
		<link>http://ztkfg.com/2026/01/bridgemaster-level-4-b-30-stumbling-on-a-trump-squeeze/</link>
		<comments>http://ztkfg.com/2026/01/bridgemaster-level-4-b-30-stumbling-on-a-trump-squeeze/#comments</comments>
		<pubDate>Sat, 10 Jan 2026 01:47:37 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Contract Bridge]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=548</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




 

North&#9824;︎5432&#9829;︎432&#9830;︎AK4&#9827;︎QJ10


BBO Viewer
Bridge Solver




West&#9824;︎76&#9829;︎65&#9830;︎8765&#9827;︎AK432




W
N
E
S





2&#9824;︎
3&#9829;︎
P


4&#9829;︎







East&#9824;︎KQJ1098&#9829;︎87&#9830;︎Q109&#9827;︎65



WillHaack&#9824;︎A&#9829;︎AKQJ109&#9830;︎J32&#9827;︎987

4&#9829;︎ E





 Once again the bidding box is wrong, east dealt and bid 2S, south overcalled 3H, and north took south to game. 
West played 3 rounds of clubs, east ruffed the third round and returned a spade to declarer's ace. I drew trumps and on the second trump when east showed [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




 

North&#9824;︎5432&#9829;︎432&#9830;︎AK4&#9827;︎QJ10


BBO Viewer
Bridge Solver




West&#9824;︎76&#9829;︎65&#9830;︎8765&#9827;︎AK432




W
N
E
S





2&#9824;︎
3&#9829;︎
P


4&#9829;︎







East&#9824;︎KQJ1098&#9829;︎87&#9830;︎Q109&#9827;︎65



WillHaack&#9824;︎A&#9829;︎AKQJ109&#9830;︎J32&#9827;︎987

4&#9829;︎ E





 Once again the bidding box is wrong, east dealt and bid 2S, south overcalled 3H, and north took south to game. 
West played 3 rounds of clubs, east ruffed the third round and returned a spade to declarer's ace. I drew trumps and on the second trump when east showed [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/bridgemaster-level-4-b-30-stumbling-on-a-trump-squeeze/feed/</wfw:commentRss>
		</item>
		<item>
		<title>bitcoindexplorer node report</title>
		<link>http://ztkfg.com/2026/01/bitcoindexplorer-updates/</link>
		<comments>http://ztkfg.com/2026/01/bitcoindexplorer-updates/#comments</comments>
		<pubDate>Thu, 08 Jan 2026 22:02:58 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Bitcoin]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=549</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==bitcoindexplorer.com is down to 1 mirror and the bitcoin node that backs that mirror is far behind the tip of the chain. When I restart bitcoind, it starts to catch up at a decent rate, but then it chokes and gets stuck indefinitely after a couple of hours. I currently have a cronjob restarting bitcoind [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==bitcoindexplorer.com is down to 1 mirror and the bitcoin node that backs that mirror is far behind the tip of the chain. When I restart bitcoind, it starts to catch up at a decent rate, but then it chokes and gets stuck indefinitely after a couple of hours. I currently have a cronjob restarting bitcoind [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/bitcoindexplorer-updates/feed/</wfw:commentRss>
		</item>
		<item>
		<title>BridgeMaster Level 4 Deal B-29, The Vice</title>
		<link>http://ztkfg.com/2026/01/bridgemaster-level-4-deal-b-29/</link>
		<comments>http://ztkfg.com/2026/01/bridgemaster-level-4-deal-b-29/#comments</comments>
		<pubDate>Thu, 08 Jan 2026 15:26:04 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Contract Bridge]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=547</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




 

North&#9824;︎AK65&#9829;︎932&#9830;︎AKQJ&#9827;︎32


BBO Viewer
Bridge Solver




West&#9824;︎Q1098&#9829;︎J1087&#9830;︎6&#9827;︎7654




W
N
E
S





1NT
P
2&#9827;︎


P
2&#9830;︎
P
6NT




East&#9824;︎J7&#9829;︎A654&#9830;︎10987&#9827;︎1098



WillHaack&#9824;︎432&#9829;︎KQ&#9830;︎5432&#9827;︎AKQJ

6NT S





Once again the handviewer bidding is bugged, the contract is played by south. 
Let's go over how I got this problem wrong. 
West leads the jack of hearts which rides up to your king. Plan your play. 
I knew that the problem had something to do with a squeeze and squashing [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




 

North&#9824;︎AK65&#9829;︎932&#9830;︎AKQJ&#9827;︎32


BBO Viewer
Bridge Solver




West&#9824;︎Q1098&#9829;︎J1087&#9830;︎6&#9827;︎7654




W
N
E
S





1NT
P
2&#9827;︎


P
2&#9830;︎
P
6NT




East&#9824;︎J7&#9829;︎A654&#9830;︎10987&#9827;︎1098



WillHaack&#9824;︎432&#9829;︎KQ&#9830;︎5432&#9827;︎AKQJ

6NT S





Once again the handviewer bidding is bugged, the contract is played by south. 
Let's go over how I got this problem wrong. 
West leads the jack of hearts which rides up to your king. Plan your play. 
I knew that the problem had something to do with a squeeze and squashing [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/bridgemaster-level-4-deal-b-29/feed/</wfw:commentRss>
		</item>
		<item>
		<title>Missing a (point) count on the hand</title>
		<link>http://ztkfg.com/2026/01/missing-a-point-count/</link>
		<comments>http://ztkfg.com/2026/01/missing-a-point-count/#comments</comments>
		<pubDate>Sun, 04 Jan 2026 21:12:27 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Contract Bridge]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=546</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==





18


will22&#9824;︎Q43&#9829;︎42&#9830;︎852&#9827;︎KJ865


BBO Viewer
Bridge Solver




4harcor&#9824;︎76&#9829;︎J5&#9830;︎QJ109&#9827;︎Q10972




W
N
E
S





P
1&#9829;︎
1&#9824;︎


X
2&#9824;︎
3&#9830;︎
4&#9824;︎




jjbridg&#9824;︎52&#9829;︎KQ1063&#9830;︎AK763&#9827;︎3



WillHaack&#9824;︎AKJ1098&#9829;︎A987&#9830;︎4&#9827;︎A4

4&#9824;︎ S





West led the jack of hearts and I took it with my ace and played the same suit to setup for a ruff. RHO won the heart with the 10 and played the king and ace of diamonds, I ruffed the second round. I drew one round of trumps and played a [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==





18


will22&#9824;︎Q43&#9829;︎42&#9830;︎852&#9827;︎KJ865


BBO Viewer
Bridge Solver




4harcor&#9824;︎76&#9829;︎J5&#9830;︎QJ109&#9827;︎Q10972




W
N
E
S





P
1&#9829;︎
1&#9824;︎


X
2&#9824;︎
3&#9830;︎
4&#9824;︎




jjbridg&#9824;︎52&#9829;︎KQ1063&#9830;︎AK763&#9827;︎3



WillHaack&#9824;︎AKJ1098&#9829;︎A987&#9830;︎4&#9827;︎A4

4&#9824;︎ S





West led the jack of hearts and I took it with my ace and played the same suit to setup for a ruff. RHO won the heart with the 10 and played the king and ace of diamonds, I ruffed the second round. I drew one round of trumps and played a [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/missing-a-point-count/feed/</wfw:commentRss>
		</item>
		<item>
		<title>On Getting Better at Bridge</title>
		<link>http://ztkfg.com/2026/01/on-getting-better-at-bridge/</link>
		<comments>http://ztkfg.com/2026/01/on-getting-better-at-bridge/#comments</comments>
		<pubDate>Fri, 02 Jan 2026 16:35:22 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Contract Bridge]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=544</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==From my limited experience in tournament bridge, it seems that the most important quality of a good player is the ability to remain concentrated and avoid careless mistakes. 
At first, the ability seems natural to some and is impossible for others (me) to achieve. It has been frustrating learning how to do more complicated endplay [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==From my limited experience in tournament bridge, it seems that the most important quality of a good player is the ability to remain concentrated and avoid careless mistakes. 
At first, the ability seems natural to some and is impossible for others (me) to achieve. It has been frustrating learning how to do more complicated endplay [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2026/01/on-getting-better-at-bridge/feed/</wfw:commentRss>
		</item>
		<item>
		<title>Entries, timing, establishment, promotion, this hand has a lot!</title>
		<link>http://ztkfg.com/2025/12/stumbling-on-entries-and-timing/</link>
		<comments>http://ztkfg.com/2025/12/stumbling-on-entries-and-timing/#comments</comments>
		<pubDate>Wed, 31 Dec 2025 03:03:28 +0000</pubDate>
		<dc:creator>whaack</dc:creator>
		
		<category><![CDATA[Contract Bridge]]></category>

		<guid isPermaLink="false">http://ztkfg.com/?p=542</guid>
		<description><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




11

creich&#9824;︎AQ9765&#9829;︎K6&#9830;︎AQ84&#9827;︎Q


BBO Viewer
Bridge Solver




Basden&#9824;︎J108&#9829;︎1032&#9830;︎KJ652&#9827;︎93




W
N
E
S







1&#9827;︎


P
1&#9824;︎
P
2&#9829;︎


P
2&#9824;︎
P
3&#9829;︎


P
4NT
P
5&#9830;︎


P
6&#9829;︎






marylousch&#9824;︎432&#9829;︎Q75&#9830;︎1097&#9827;︎AJ42



WillHaack&#9824;︎K&#9829;︎AJ984&#9830;︎3&#9827;︎K108765

6&#9829;︎ S





I reversed to show my shape1, consequently partner took me to 6 hearts despite his 2 card support. West kindly led a heart, and I took east's queen with my ace. How would you plan your play? 
Trumps need to be 3-3 or the 10 must fall doubleton to make. If spades [...]]]></description>
			<content:encoded><![CDATA[NDUzNTUzNjI5NDJ8MjE2LjczLjIxNi40MQ==




11

creich&#9824;︎AQ9765&#9829;︎K6&#9830;︎AQ84&#9827;︎Q


BBO Viewer
Bridge Solver




Basden&#9824;︎J108&#9829;︎1032&#9830;︎KJ652&#9827;︎93




W
N
E
S







1&#9827;︎


P
1&#9824;︎
P
2&#9829;︎


P
2&#9824;︎
P
3&#9829;︎


P
4NT
P
5&#9830;︎


P
6&#9829;︎






marylousch&#9824;︎432&#9829;︎Q75&#9830;︎1097&#9827;︎AJ42



WillHaack&#9824;︎K&#9829;︎AJ984&#9830;︎3&#9827;︎K108765

6&#9829;︎ S





I reversed to show my shape1, consequently partner took me to 6 hearts despite his 2 card support. West kindly led a heart, and I took east's queen with my ace. How would you plan your play? 
Trumps need to be 3-3 or the 10 must fall doubleton to make. If spades [...]]]></content:encoded>
			<wfw:commentRss>http://ztkfg.com/2025/12/stumbling-on-entries-and-timing/feed/</wfw:commentRss>
		</item>
	</channel>
</rss>
